Atari 800XL PSU and caps replacement

[repetto74]

Hi,

 

the PSU of my 800 XL is this one below

 

3) CO61763-11

Input: 220VAC 50Hz 26VA

Output: 5VDC 1,5A

 

Fuse: T 2.5A

 

Thermal fuse: 125 degr.C

T40/E

 

Approval signs: VDE (German) GS (Geprüfte Sicherheit (="tested safety", German)

 

Brand: FWGB which stands for Friwo Gerätebau GmbH. from Germany

 

Notes: The FW1599 Typenr. is a factory Friwo number. Although it doesn't say it was made in Germany it was produced by a German company and the unit is over a very very good quality. Construction, lay-out are excellent. I haven't checked the schematics, but the set-up is pretty extensive for a "simple" 5V DC power supply.

 

The big filter cap is of the Frako brand (www.frako.com), a very high quality German capacitor brand. FRAKO stands for FRAnkfurter KOndensatorenfabrik or "capacitor factory of Frankfurt". I couldn't see the brand of the smaller caps but I measured all of them with a high quality ESR meter and all show excellent values still.

I think this supply is the most common one for the XLs around here and my preferred power supply.

I am glad to hear it is a quality one compared to others. I have checked the PSU pcb recently and did not noted anything suspicious but was thinking to replace the tree elec caps as a precaution. I have a doubt concerning the two 100uF 25V caps as I am not sure if they are or not polarised. Both caps have a white band on one side so I assume this is to identify the negative lead? It is the first time I see caps with this odd marking.

Thanks

Rick

[Level42]

Hey Rick....

 

I'd have to open mine up again to check, can you post pictures ?

 

I'd personally check the caps with a good ESR meter but not everyone has one of course.

 

You can also check for any poor cap performance by measuring the output voltage with a multi-meter in _AC_ setting to measure any ripple.

 

Be sure to get QUALITY replacement caps, Nichicon and Panasonic are good brands, Panasonic usually a bit cheaper. While you are at it, buy 105 degree ones with a low ESR. It's worth investing a bit more if you take the trouble to replace them.

[repetto74]

Hi Level42,

 

I have this picture here if that can help otherwise I may open the PSU case again and take some better pictures.

 

As you can see I do not know if the two 100uF caps are or not polarised.

 

[Level42]

Hi Level42,

 

I have this picture here if that can help otherwise I may open the PSU case again and take some better pictures.

 

As you can see I do not know if the two 100uF caps are or not polarised.

 

 

Yes those are DEFINITLY polarized. They are electrolytic caps just like the bigger ones.

[repetto74]

Hi Level42,

 

Good! I will replace the three of them for precaution then. I have them in stock here with me so it will be a quick job to do :-).

 

Thanks a lot.

Rick

[Level42]

I so hope you have goog quality ones, not Chinese no-name caps since you might actually make things worse with those...

 

Could you do me a favor and ID the brand of the smaller caps (maybe a sharp close-up picture) ? I see the big ones are Nippon Chemi-Con on your picture....

[repetto74]

Hi Level42,

 

I will open the PSU tomorrow and let you know the brand no problem . Yes the replacement caps are good quality ones I bought from my local electronic reseller here.

[repetto74]

Hi Level42

 

Here is a picture of one of the 100 uF cap I removed today. There is no name on it but if you zoom the picture there is a small logo and you may guess the brand

 

Cheers,

Rick