View Full Version : Slightly off topic - VCR power supply


sweitzel
08-09-2007, 05:22 PM
I've been trying to locate knowledgeable folks who know a thing or two about solid state power supplies. I have a Panasonic AG1980p svhs editing deck that I would love to resurrect. The problem is the power supply brick (part VEP01617A) is toast.. It's only putting out 8 volts on the 36 volt bus. I have the service guide and have a parts list. Most of what I have tried to test with a VOM show correct values. Apparently the power supplies in this particular deck are prone to failure because I see these decks on ebay all the time with the same problem (very dim display and no mechanical response) Does anyone know if there is a specific common failure part in these supplies or know where one could get a replacement supply? Some of the online parts houses show the supply, but it is listed NLA. I suspect it might be a bad IC or transformer, but even those parts are NLA. If not, can someone point me to a web forum that might be better suited to my question here? Thanks in advance.

andy
08-09-2007, 06:34 PM
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Findm-Keepm
08-09-2007, 10:09 PM
Several parts distributors used to sell the kits of most-commonly failed parts for these. These were shotgun affairs - basically all of the caps and a few other parts. Andy is dead on - high ESR is the killer of these power supplies.

I was unable to find one for the VEP01617A, but MAT Electronics (no connection/affiliation, but I have purchsed from them before) has two oother VEP kits listed:

Panasonic Type VEPS0167 SMPS Repair Kit
- PROVIDES THE NECESSARY COMPONENTS TO REPAIR 95% OF ALL FAILURES IN THE SWITCH MODE POWER SUPPLY.
- CONTAINS: (1) 1.6A GMA FUSE, (1) DB104 BRIDGE RECTIFIER, (1) EG01 DIODE, (1) 2SC4130, (1) 2SB643, (1) MA165 DIODE, (1) MA130 DIODE, (1) TLP621 OPTO ISOLATOR, (1) 82uF/200V, (1) 1uF/50V, (2) 330uF/6.3V, (1) 6.2V, 1/2W ZENER DIODE

= And =

Panasonic Type VEP0172 SMPS Repair Kit
- PROVIDES THE NECESSARY COMPONENTS TO REPAIR 95% OF ALL FAILURES IN THE SWITCH MODE POWER SUPPLY.
- CONTAINS: (1) 1.6A GMA, (1) DB104 BRIDGE RECTIFIER, (1) EG01 DIODE, (1) 2SC4073, (1) 2SD1458, (2) MA165 DIODES, (1) TLP621 OPTO ISOLATOR, (1) 1uF/50V, (2) 330uF/6.3V, (1) 82uF/200V, (2) 330uF/16V

Your mileage may vary, but I've shotgunned the listed parts and fixed a few - most of these were junked due to the lower cost in replacing them.

Hope this helps -

Cheers

waltchan
08-09-2007, 11:48 PM
AG-1980P qualifies as a cheaply-made new VCRs. The power supply is standard size and uses the same components from the PV units. Replacing all the caps at the power supply will cure 80% of the problems. If you are still unsure, go to studiosoundelectronics.com and use the ask a tech page for more details.

sweitzel
08-10-2007, 12:00 PM
thanks guys, i will examine all of these options and report the outcome.

andy
08-10-2007, 12:12 PM
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sweitzel
08-10-2007, 01:38 PM
Since i have the service manual which has the parts list, I just went ahead and ordered all of the caps and diodes from mouser and partsstore.com cost about $25 bucks in all. We'll see if that whips it into shape.

waltchan
08-10-2007, 07:45 PM
Properly woking AG-1980s are still worth good money, but they are getting harder and harder to find. None of the ones with the original caps are likely to work properly for much longer.
Do you have any idea what kind of chassis it is in the AG-1980? What it looks like?

andy
08-11-2007, 03:33 AM
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waltchan
08-11-2007, 09:38 AM
The tape transport is similar to the consumer transport that came out in mid 1987. It has some improvements such as using a separate loading motor instead of the capstan motor.
Is it the one from the PV-1730, AG-1960, or AG-1820?