Hi everyone,
I'm refurbing a non-working DVR (won't power up) and starting by replacing the caps in the PSU PCB section. All caps are Aishi and some have already tested bad and will be replaced, however I have a quick question:
There's a bunch of 1000uF 16V caps, but one is taller than the others. The majority are marked CD288Z, and the taller one is CD288S. A quick Web search has not turned up any useful info, so can anyone let me know from experience whether there's any major differences between the two types that may be relevant for how I replace them. I presume...
linker3000
Member
Last Activity: 05-07-2019, 02:01 PM
Joined: 09-11-2007
Location: West Sussex
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Aishi Capacitors (same value, different height)
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Re: Aishi capacitors
(Yay for old threads)
I'm just starting my journey through a Curtis-brand UK freeview DVR (DVB350UK) that won't power up. You can hear the power circuit trying though!
All caps are Aishi and the first two pulls are CD288Z 1000uF 25V with obvious top bulge.
First cap reads as 108uF with an ESR of 4.7R, second reads open circuit.
For control, a new replacement Panasonic FR reads 1009uF with an ESR of 0.59R
I'm going to replace the caps in the PSU circuit and hope the remainder (about 15... -
Re: ESR meter upgrades
Yes....Leave a comment:
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Re: ESR meter upgrades
Just to clarify, all the parts I listed in my previous post are bipolar transistors. The list shows which ones are detected correctly and which are incorrectly identified as either FETs or diode pairs.Leave a comment:
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Re: ESR meter upgrades
Samples from the parts drawer:
Correct
TIP42A
TIP32B
BCY70
2N4036
ZTX651
2N3906
MJ1410
Two diodes
SE9302
BD139
BFY50
BF494
2N3053
N-JFET
BCY65E
BC182L
BC650
2SC546
BC107
ZTX300...Leave a comment:
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Re: ESR meter upgrades
Now reflashed and running OK. Calibrated OK, but like the other firmware I tried it has problems with small signal transistors which can either report as JFETs or a pair of diodes. If I revert to the original firmware the transistors check as expected.
Happy to check out any suggestions or stick with the original firmware if there's no desire to look into this.
Thanks either way.Leave a comment:
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Re: ESR meter upgrades
Duh! Copied the instruction verbatim from the accompanying text file. Will redo in three steps....Last edited by linker3000; 08-12-2016, 02:18 PM.Leave a comment:
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Re: ESR meter upgrades
So good I did it twice:
[CODE]C:\temp\mk328>avrdude -c USBasp -p m328p -U flash:w:TransistorTester.hex \-U eeprom:w:TransistorTester.eep \-U lfuse:w:0xf7:m \-U hfuse:w:0xd9:m \-U efuse:w:0xfc:m
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.04s
avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed...Last edited by linker3000; 08-12-2016, 12:59 PM.Leave a comment:
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Re: ESR meter upgrades
I tried calibrating both of these with the results as listed:
GM328_EZM_v1.12k_r541: Board is hard to turn on. Seems to perform most tests OK but often incorrectly identifies small signal transistors as JFETs
mega328_GM328 from current trunk at the same repo: Board turns on, but ditto with the small signal transistors....Leave a comment:
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Re: ESR meter upgrades
USBASP Windows 10 with avrdude -c USBasp -p m328p -U flash:w:TransistorTester.hex \-U eeprom:w:TransistorTester.eep \-U lfuse:w:0xf7:m \-U hfuse:w:0xd9:m \-U efuse:w:0xfc:m
328P's fitted into an Uno.
I have just flashed the target chip with Blink through the Arduino IDE/USBASP as a test and the LEDs blinking away....Leave a comment:
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Re: ESR meter upgrades
I've just had a quick look at the board at that link and mine does not have RV1 fitted....Leave a comment:
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Re: ESR meter upgrades
Just tried it.. the board starts up, the LED display goes solid black with the top shimmering and then after about 2 secs it shuts down.
That was with the files from GM328x ESR tester (SVN684) - v2.zip\GM328x ESR tester (SVN684) - v2\original 8MHz\...Leave a comment:
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Re: ESR meter upgrades
Yes, that's it....Leave a comment:
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Re: ESR meter upgrades
Hi,
I have just read through 33 pages of messages and kudos to everyone involved for working through the coding, testing and updates!
I am wondering if any of the firmware bundles will work with my board - it's marked as EZM Electronics Studio M328_9V_V3.3 2014.10.22. I have tried a couple of other firmware variants with mixed success:
GM328_EZM_v1.12k_r541: Board is hard to turn on. Seems to perform most tests OK but often incorrectly identifies small signal transistors as JFETs
mega328_GM328 from current...Leave a comment:
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TRENDnet TEW-671BR dual band wireless router reset issue fixed
Symptoms: Approx every 2-3 weeks the router would reset to factory defaults. If re-setup it would be fine for a short period before resetting again.
Replaced all its electrolytic capacitors and the router has been fine ever since.
Replaced:
5 x 470uF 16V radials (ESR approx 0.45R for each)
1 x 100uF 25V radial ('disappeared' before ESR could be tested)
The plastic wrapping on two of the 470uF caps had split, suggesting a bit of deformation.
All caps were 105C Jackcon "Low ESR"; the 470uF ones were marked "0209C"....Last edited by linker3000; 07-30-2016, 05:56 AM. -
The SMPSU equivalent of 'fingernails on the blackboard'
Just looking at this one sets my teeth on edge.
This board is from a no-name RGB LED DMX PAR lamp (they're all over your favourite auction site and tat bazaars); it's rated at 12V 3A and joined the afterlife with a whomp. The IEC inlet contained a 1A fuse (vaporized), but the board also had a through-hole one, which was similarly toasted. There's no inrush limiting, nor mains EMI filtering. As a sidenote: the lamp unit has an IEC socket and a plug to allow for daisy-chaining, but the earth pins aren't linked, so it would be all fun and games if something down... -
Re: Netgear Prosafe JGS516 switch with Delta Electronics ADP-40VP PSU board (fixed)
Starting capacitor replaced - it was 47uF 25V
Thanks everyone for your input.Leave a comment:
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Re: Netgear Prosafe JGS516 switch with Delta Electronics ADP-40VP PSU board (fixed)
Yeah, it'll bug me if I don't do it anyway, so it'll come out soon! Any suggestions on working voltage as it's encased in the mounting goop from the 400V cap.
Edit: Since SMPSU design is one area of electronics I've not really 'got into' in the past, I've just done some reading up and it seems that the little 47uF startup cap can be the source of quite a bit of hassle!
It looks like a 50V/63V one will be OK - does that sound reasonable?Last edited by linker3000; 01-06-2016, 05:24 PM.Leave a comment:
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Re: Netgear Prosafe JGS516 switch with Delta Electronics ADP-40VP PSU board (fixed)
I actually called it a day in the home workshop without doing the last cap - let's see if that comes back to bite me later!Leave a comment:
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Netgear Prosafe JGS516 switch with Delta Electronics ADP-40VP PSU board (fixed)
Typical symptoms: The switch had been powered up and working for several years and was then switched off for an office refurb, never to power up again. The unit contains a Delta ADP-40VP 5V 8A SMPSU board and the output measured 1.6V
There were 4 suspect caps with no outward signs of distress - all Ltec:
1 x 1500uF 10V - replaced with Panasonic 105C FR
3 x 2200uF 10V - replaced with Panasonic 105C FR
I decided I might as well replace the HV smoothing cap while I was in there (100uF 400V Ltec), so in went a Chemicon KXG.
There was also a...Last edited by linker3000; 01-06-2016, 04:35 PM.
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