Delta DPS-214CP PSU no standby (Grundig TV)

[Dannyx]

Good day folks. Bit of help with this telly here ? It's got the PSU in the schematic attached and it's got no power at all. I managed to track down the issue to the standby IC, IC901, a DDA010 which is apparently the same thing as a ICE2QR0665 (datasheet below for your convenience). Initially, I found R902 (slightly above and to the right of the IC in the schematic) had gone open circuit. I replaced it and still get nothing. Now I can only assume that the startup cell inside the IC is not working (page 7 of datasheet explains how it SHOULD work). From what I can assume, during startup the VCC pin sources some current from the drain pin until the AUX winding starts operating on its own and sustains the operation. I'll post some pics of the PSU soon, but for the time being is it safe to assume it's the IC itself that's faulty ? I checked the diodes and didn't get any shorts. The VCC pin appears totally dead - not even "bursts" or startup attempts. Nothing at all, so I don't suppose it's a faulty cap we're talking about. Cheers and thanks.

[dick_barton]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

It may be worth reading the last post in the following thread

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

I had a read through it but the difference is that I'm not getting squat, whereas the OP there did get some fluctuations on VCC....I don't have a scope sadly, but from what I can tell, there's no activity on the VCC pin at all....of course I checked all my passives around that IC and they seem fine. I wonder if they ever found a fix. I'll start by replacing the IC then work my way from there...maybe I'll get lucky.

UPDATE: I made another discovery: PC902 has 2v on its emitter pin (the one going into ZD904)...don't know if that's of some major importance though. It's extremely confusing where those 2v are coming from, considering the rest of the circuit appears "dead"...

[dick_barton]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Have you checked R601 which looks as though it acts as a fuse.

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Have you checked R601 which looks as though it acts as a fuse.

Yes - I get continuity through it.

[dick_barton]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Yes - I get continuity through it.

What dc voltage if any do you have at D902 and does C903 measure ESR/capacitance OK

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Output of D902 is dead like I said, since it corresponds to the VCC pin of the IC. Haven't replaced that cap yet, but I'm not getting anything on that line anyway so I doubt it's the cap to blame....for now at least.

[dick_barton]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

If you lift the cathode of the diode D902, can you see any voltage at the cathode at switch on?

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

I shall try tmmoz.

[jetadm123]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Are you getting 330VDC across the main filter cap? If yes, then unplug power supply and measure across the VCC and ground pins of IC901 for a short.

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Yes I am getting 330v on the caps. No shorts anywhere. It was the first thing I checked for and then double checked, unless there's indeed a component I'm missing.

[jetadm123]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

you can try heating up the startup cap with a hair dryer to see if anything happens. If not, I would suggest replacing IC901.

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

I was going to replace it anyway, though I doubt it's going to be that simple after reading the other post about a similar problem...albeit that one had slightly different symptoms and the OP got some VCC there, whereas I get nothing, no voltage at all on that VCC bus. HOWEVER what I haven't tried so far is measuring that VCC node immediately upon startup to see if it bumps even a little bit. If it doesn't, the startup cell inside IC901 is dead.

[budm]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

What is the resistance between VCC and GND? I did not see hat reading.

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Haven't measured yet. Will have to do that too.

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

What is the resistance between VCC and GND? I did not see hat reading.

With the negative probe on VCC and the positive one on primary GND it's around 35kOhms.
Also, lifting the cathode of D902 and measuring it I get 3v.

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

I sent my buddy to the nearest radioshack to look for that IC901 and it turns out it's pretty pricey. Wasn't expecting it to be this expensive. Not sure whether to go for it, esp since it doesn't guarantee it'll fix the issue. Granted, I could PROBABLY find cheaper alternatives online since retail stores by nature have higher prices, makes perfect sense, but I haven't really looked into it too deep yet. If someone has a brainy idea or has got hold of one of these before cheaper, let me know pls

[WildPuppy]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Check the price and specs for ICE3B0565 as it may be a cheaper replacement than DDA010.
Source: HERE
Possible order @ Adeliaida

[Dannyx]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

Since you're a "homie" of mine and I reckon we use the same currency, for comparison, the shop asked 70 RON for it, whereas at Adelaida it would be around 50 RON (+shipping)...not that much of a difference. The guy looked for the ICE one as well, not the original DD. It's up to the client at the end of the day....

[dick_barton]

Re: Delta DPS-214CP PSU no standby (Grundig TV)

With D902 cathode lifted what voltage does VCC pin of DDA010 reach. The internal charge pump should be outputting a voltage to charge C903. The internal charging circuit then switches off when C903 voltage reaches => 10.5V typically.

Do you have the B+ voltage on pins 4 & 5 of the DDA010