AU-717 restoration

zebulon1

zebulon1

Working on my own stuff. Finally
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I am restoring a 717 and have some question concerning the cap replacements on the power/protection board F-2663. Caps c29, c30 and c604.

The caps I removed from the protection circuit are not the same values stated on the schematic. I can tell this is not the first repair due to a terrible glue removal job on this very same board. I think the previous tech replaced the caps with whatever he had on hand. The values and voltage specs are different. Does anyone have a recap list, or road tested knowledge I could check against?

This set was inop when I received it and when I looked at the boards with all the rot due to the adhesive, I just started the resto without repairing it first. Mistake?

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The caps for C-29 and C-30 are BI-POLAR and are listed on my schemy as 100uF @ 6.3V. C-604 is 330uF @ 10V.

I have successfully used 220uF for the bi-polars and 470uF for C-604 (real world) with no issues.
 
Good deal. Thanks for the tips. I think that completes my order list. Of course I will go over it again several times and then forget something for sure.
 
It is NOT a good idea to refer to Sansui schematics for the values of capacitors for replacement. Values on the schematics did not keep up with production changes. Put back in the same value components that were fitted, but make sure you check nobody has been 'in there' before.
 
All of the 717's that I have restored have had 220uf 6.3V bi polars for C29 and C30 as the original fitment. Other than these two, the original caps fitted have agreed with the schematic in the ones that I have restored. But as Hyperion has stated, the schematics don't necessarily agree with what was fitted, and you should always replace with the same value that was originally fitted.

Cheers

John
 
The ones I pulled were ironically the off values Kico mention in his reply (220uF for the bi-polars and 470uF for C-604).

Is the schematic the only place to fine the component values? Is there a equipment list somewhere?
 
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F-2663 is the powersupply board. Yep those r the correct values for those position caps u mentioned.

If u do decided to restore the whole board, probably the relay box do nd some attention as well as over the years the copper contacts tends to pit(darkened surface) thus unable to provide gd contact to it.

Bascially on top of the relay box, a mini spring is securing it pt. Release n slide up carefully to expose it. I polished mine wif autosol n lube it wif progold aft the process.

Of cos u cld replace it wif a new unit(Omron MY4-02-24VDC) if u find the procedure a hassle :thmbsp:

Jen
 
I think I found the culprit. It wasn’t even attached. There was two of these rotted ones on the left side of the board.

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zebulon1 said:
I think I found the culprit. It wasn’t even attached. There was two of these rotted ones on the left side of the board.

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This is the reason I replaced every single cap in my 717.
Replacing these one at time, or worse, paying someone to do it, gets old real fast.
 
A lot of person are complaining about the fact that it is very hard to remove the glue used to secure the electrolytic capacitors. First I agree and sympatized with them. Second, there is a easy solution. The solvent that I use is toluol available at a hardware and auto parts store. This product is very flamable and the job should be done in a well ventilated area. Dip a Q-Tip in toluol and wet the area where the glue is located. Keep on doing it for five to seven minutes until it turns into a gell. I use a piece of pc board (5mm x 40mm) to scrape it off. Wipe the rest with a moist cloth or Q-Tip and the job is done. Yes, it is that easy and it saves a lot of elbow grease.
 
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