Spectroniq PLTV-3250 wont start

[user_007]

Re: Spectroniq PLTV-3250 wont start

Bumping this thread...hopefully someone can help me?

I picked up this TV with a bad PSU. Opened it up and saw 3 bulging capacitors. Replaced those, ESR tested the others and found another bad one, replaced it as well.

Had no standby voltage.

I read through this thread and other sites, and saw about ZD4 and Q7. Tested ZD4, and sure enough, it had continuity in both directions. Replaced it, but still no luck. Next, replaced Q7 with a 2222 (not surface mount style, but managed to get it to fit).

Plugged it in, and got 5v standby. I was happy, thought I'd solved the issue. However, the PSU still will not power on.

I've tested the TV and I am getting 3.3 V on the I/O pin, so the logic board or whatever seems to be working fine. But the PSU itself still won't power on (I cannot get 16 or 24 V).

Has anyone experienced this type of failure, or have any advice on where to proceed next? I can get a new one for less than $70, but if I can fix the old power supply, that's preferable.

Thanks.

[PlainBill]

Re: Spectroniq PLTV-3250 wont start

Bumping this thread...hopefully someone can help me?

I picked up this TV with a bad PSU. Opened it up and saw 3 bulging capacitors. Replaced those, ESR tested the others and found another bad one, replaced it as well.

Had no standby voltage.

I read through this thread and other sites, and saw about ZD4 and Q7. Tested ZD4, and sure enough, it had continuity in both directions. Replaced it, but still no luck. Next, replaced Q7 with a 2222 (not surface mount style, but managed to get it to fit).

Plugged it in, and got 5v standby. I was happy, thought I'd solved the issue. However, the PSU still will not power on.

I've tested the TV and I am getting 3.3 V on the I/O pin, so the logic board or whatever seems to be working fine. But the PSU itself still won't power on (I cannot get 16 or 24 V).

Has anyone experienced this type of failure, or have any advice on where to proceed next? I can get a new one for less than $70, but if I can fix the old power supply, that's preferable.

Thanks.

I'd like to help you, really I would. But without pictures of YOUR power supply I really can't suggest anything.

PlainBill

[user_007]

Re: Spectroniq PLTV-3250 wont start

Thanks for your response. Will post pictures shortly.

[user_007]

Re: Spectroniq PLTV-3250 wont start

Here are some pictures of both sides of the board. There is definitely what appears to be discoloration from heat on both sides of the board near Q4. I popped Q4 out of circuit and checked it with the diode check setting on my DMM, and there were no shorts.

Also tested ZD3 and it appears fine.

The area around Q7/ZD4/C33 is a bit messy. Q7 is now a MPS2222a. The solder pad on C33 came loose as I was desoldering it (carefully too, didn't think I had too much heat), so I traced the route along the board and jumped it to the next pin. There are no shorts in that area, however, I have made sure that everything is spaced apart, and I put electrical tape between all connections before testing.

C33 is original, however...tested the ESR both in and out of circuit and got about 1.2 ohms, which seems acceptable. Is it worth replacing anyway? I don't have any 33 uf caps around, and can't get any locally, so would have to order some. I didn't think it'd be likely to help, seeing as the ESR is OK.

6 caps were actually replaced in total (5 larger ones and C32). All caps in there right now measure good ESR.

[retiredcaps]

Re: Spectroniq PLTV-3250 wont start

C33 is original, however...tested the ESR both in and out of circuit and got about 1.2 ohms, which seems acceptable. Is it worth replacing anyway?

Just for comparison, a Panasonic FC cap at 33uF 35V according to

http://search.digikey.com/scripts/Dk...name=P10290-ND



is 0.08 ohms

The FC is not Panasonic's lowest ESR family. FM has lower ESR, but it is not available in 33uF.

So your cap is 15 times more than FC. Is 1.2 ohm bad or not?

For me, 33 cents to buy a quality low ESR FC cap vs $70 for a replacement board with potentially crappy caps, I would switch it out.

[user_007]

Re: Spectroniq PLTV-3250 wont start

Hmm, then I guess it is bad ESR? I was using the chart on the front of my meter, in which the ESR doesn't seem out of the ordinary.

http://img522.*************/img522/4056/sd530057yq6.jpg

So you would think that cap could be bad?

[retiredcaps]

Re: Spectroniq PLTV-3250 wont start

I was using the chart on the front of my meter, in which the ESR doesn't seem out of the ordinary.

I don't know about the chart, but SMPS applications require low ESR caps.

I can't definitely say that the cap is bad, but most here recommend that you replace ALL caps (especially if they are Capxon) since you already found 3 bulgers + 1 high ESR. 15x seems very high to me.

PS. Members here hate off site picture posts. I have gone to imageshack more than once to view a picture. When I click on the picture to get a bigger view, I'm greeted with popup spam (partypoker) or some other site.

[user_007]

Re: Spectroniq PLTV-3250 wont start

Sorry about that, was just a picture I found from Google images of the chart I was looking at. I'll be sure to upload all of my pictures as attachments.

Anyway, I found a 33 uf cap in a multipack at RadioShack - I'm sure they're not the highest quality caps, but seeing as how I was able to get it tonight, I figure I'll give it a try. Will let you know if it helps.

Thanks again for all the help.

[retiredcaps]

Re: Spectroniq PLTV-3250 wont start

Anyway, I found a 33 uf cap in a multipack at RadioShack - I'm sure they're not the highest quality caps, but seeing as how I was able to get it tonight, I figure I'll give it a try.

Measure and report the ESR of 33uF RadioShack. I'm sure most here are curious about the reading.

[user_007]

Re: Spectroniq PLTV-3250 wont start

Put in the new cap from RadioShack, no change. Still getting 5v standby, but no 16 or 24v.

ESR of the RS cap is about 0.9 ohms. It's a 50V cap.

[PlainBill]

Re: Spectroniq PLTV-3250 wont start

This is a dual power supply. The 5V is standby, so that section is working. I would expect to see a line coming back from the main board that switches on the main supply.

IC1 is the SMPS controller for the main supply, IC2 is the SMPS controller for the standby supply. IC3 is the PFC controller. I'm trying to identify the control line, but can't see any legends on the connectors.

PlainBill

[retiredcaps]

Re: Spectroniq PLTV-3250 wont start

ESR of the RS cap is about 0.9 ohms. It's a 50V cap.

Well it confirms our suspicions about RadioShack selling general purpose caps and not being low ESR.

[user_007]

Re: Spectroniq PLTV-3250 wont start

Here are some views that show the legends for the connectors.

I'm getting voltage between the 5Vs and GND, as already stated. If I plug in the set and try to turn it on, I get 3.3V between the O/F pin and GND for a short time. I believe this is the signal from the main board trying to switch on the supply, as you mentioned. This tells me that the main board is working fine, correct, and it's the PSU not starting?

Thanks.

[retiredcaps]

Re: Spectroniq PLTV-3250 wont start

I forgot to ask who made the original 33uF cap? What series was it?

Was it Capxon KF?

[PlainBill]

Re: Spectroniq PLTV-3250 wont start

Here are some views that show the legends for the connectors.

I'm getting voltage between the 5Vs and GND, as already stated. If I plug in the set and try to turn it on, I get 3.3V between the O/F pin and GND for a short time. I believe this is the signal from the main board trying to switch on the supply, as you mentioned. This tells me that the main board is working fine, correct, and it's the PSU not starting?

Thanks.

Yeah, probably. You can trace the 'O/F' signal across the power supply. It appears to go to one of the two opto-isolators near the center of the board.

PlaiinBill

[user_007]

Re: Spectroniq PLTV-3250 wont start

The original 33 uF cap was a Capxon GL. I know Capxon are all pretty much crap.

If I trace the O/F pin, it appears to first go through jumper J4 then to resistor RS35. That resistor goes to the spot on the back of the board between "QS4" and "CS6" labels. From there, it seems to go through DS6 and CS15 (capacitor is across the diode?). Then it goes through RS27 (which tests good). From there seems to go to NTSC1, which is on the front of the board. From there, goes through jumper J7, where it then splits.

One side of the split goes to RS9 on the front of the board (which tests good). From there, goes to pin 1 of IC7, which is labeled:

ET1114
V 54OU27

Other side of that split goes to the solder pad directly two to the right from the bottom of CS3, which I believe is an inductor on the top of the board. That goes to the pin directly to the right of it, which goes to CS21 on the front side of the board and RS12, 13, and 14 on the back. The other side of CS21 goes to what I think might be a small transformer (I know, I should know this) - the smaller black thing between the primary and secondary side that is labeled "SPI 8TA00129 01FC HI-POT 0634 GP GH-130".

RS12, 13, and 14 all go to the same place - CS2. From CS2, I trace to the big CRS3 on the front side of the board, and to another pin on what I believe is a transformer. CRS3 then connects back to the connection where CS21 is connected to RS12, 13, and 14.

Tracing the circuit board, I'm not seeing any immediate path from the O/F pin to IC4 or IC6 that you mentioned, but it does go to IC7.

Any advice on what I should do next? Should I check IC7? I'm not exactly sure what its function is - but it does go across from secondary to primary, and is also located near the area where there seem to be heat marks from Q4.

Or am I just best to forget it and buy a new power supply? I have no imminent need for it, so I'm interested to see what's wrong with this one - but admittedly am still learning about these things.

[flyby50]

Re: Spectroniq PLTV-3250 wont start

I have a new power bord and have power and red light but no picture thanks flyby50

Just some FYI, before you go crazy trying to fix it. I know you have time, money, & sweat into the repair:

Saw 6 of these go on Ebay not 2 weeks ago for around $60 each.

Found this on the web: Electronica-USA.com

You might want to drop FSP Support a line and see if they can help.

Site: http://www.fspgroupusa.com/

and here's the page with this unit on it. You might get support to send you a schematic. Of course, with the correct amount of begging and pleading, you might get them to send you a new one since the TV manufacturer has bailed (see next bit).

BTW, this company SpectronIQ, is GONE. Saw lots of bad reports on the Ripoff Report site, this one regards their Chapter 11 filing.

Did you replace the defective caps with an equivalent type? I'm not just talking voltage and capacitance here. With an incorrect ESR, it could be they're not passing enough "juice" to kick the supply into oscillation.

Now, regarding the way to turn it on. Do you have any valid voltages at any of the outputs or connectors? I'd be looking for a good 5 volt line (or thereabouts) somewhere. Mind you, this should be a very low power (milliamps) supply voltage.

If you do, then a jumper from ground with a 150-250 ohm, 1/2 watt or better resistor should cause it to start. If you don't have a valid voltage, then your problem most likely lies farther back in the circuit.

Also, if you have the ability to reduce the input voltage (tapped isolation transformer or Variac) and bring it up slowly, by monitoring some voltages in the PSU you may discover that it starts to "come alive" and then collapses as you raise the voltage. That should give some clues as to what is failing.

Oh, eguevarae, your question:

"160v DC? Are you sure? I'm not an expert, but so far I haven't seen that DC Voltage on any PSU."

It's entirely possible, since the PSU is "un-loaded", that you could get that on a sensitive VOM as DC with an AC (RMS) element to it. The line voltage, partly rectified (1/2 wave DC) with that big cap on it could certainly produce that voltage. A scope on that voltage would show the actual waveform and perhaps a clue as to what is going on there.

Best of luck!

Toast

[wholesome]

Re: Spectroniq PLTV-3250 wont start

I have the same problem, Stand by power, can turn tv on, but no 16v or 24v. I guess this thread died.... Huh? Any more suggestions on the stand by power but nothing else?

[PlainBill]

Re: Spectroniq PLTV-3250 wont start

I have the same problem, Stand by power, can turn tv on, but no 16v or 24v. I guess this thread died.... Huh? Any more suggestions on the stand by power but nothing else?

The thread appears to have died because the OP purchased a new power supply and found he had other problems.

Tracing circuits on a power supply is not my favorite pastime, but if you want assistance troubleshooting, attach good, clear pictures of your power supply to your next post. Do not post them inline, attach them using 'Manage Attachments' - below the text entry area.

Some suggestions on the pictures: Quality, not quantity is the goal. The best pictures are close to (but not more than) 2000 x 2000 pixels. Ideally, it will be possible to read component identifiers. I would like to see two main pictures taken from directly above, without flash - one of the top of the board, one of the bottom. If necessary, one or two more that clearly show the output connectors and labels indicating the function of each pin are also very useful. And one additional point. I often have to link details at the top of the board to details on the bottom. I am much more adept at associating 'left side of top' to 'right side of bottom' than 'right side of top picture' to 'lower edge of bottom picture'.

PlainBill

[Repairtech]

Re: Spectroniq PLTV-3250 wont start

Hello I found a good picture on photo bucket
of what looks like a common 2n2222 soldered face down.

http://photobucket.com/images/New%20...power%20supply

Simple problem seems not so simple with some of
these PS .My Question is ,is Q11 the same value /specs as Q7 ?
and ZD3 reads short in circuit only, does any one know if this is normal ?
Q4 reads 600 and 522 on diode check. , fuse is good no 5 volts . no lights


I would hate to buy a 60.00 PS for what 1.50 worth of parts
could fix.



Thank You



Repairtech