Atari DD 1050 repair tips and PSU

[repetto74]

Hi guys,

 

I picked up a 1050 DD non working for a few buck and I would try my chance to repair it.

 

-the drive came with no PSU and I know it is difficult to find one but if anyone has a link where I can get one of these 9V AC PSU's. I am located in Europe and need a 220V PSU.

 

-With the hope of putting my hands on a suitable power unit I would like some tips on how to diagnose fault on this drive. Apparently the guy said the red light comes up but that's all, no sound of motor spinning or whatever. It may have a problem with the 12V line of the motor I think but will need a PSU for that. Where should I check for the 12V inputs? The 12V regulator?

 

Also what can i check now is the impedance of the read/write head to ensure it is ok. Does anyone have the resistance values at each pin of the R/W connector for me to check ?

The mechs is a TANDON.

 

Many thanks in advance.

Edited August 31, 2018 by repetto74

[flashjazzcat]

The PSUs discussed in the few posts starting here will do fine:

 

http://atariage.com/forums/topic/281972-replacement-psus/?do=findComment&comment=4095535

 

I will leave troubleshooting advice to others, since I don't have much experience repairing 1050s.

[+Nezgar]

-the drive came with no PSU and I know it is difficult to find one but if anyone has a link where I can get one of these 9V AC PSU's. I am located in Europe and need a 220V PSU.

 

-With the hope of putting my hands on a suitable power unit I would like some tips on how to diagnose fault on this drive. Apparently the guy said the red light comes up but that's all, no sound of motor spinning or whatever. It may have a problem with the 12V line of the motor I think but will need a PSU for that. Where should I check for the 12V inputs? The 12V regulator?

I wouldn't worry too much until you know you're using a proper rated PSU before assuming there's any issues with it. The 12V side draws the most power when the motor is spinning, and will not work properly if either DC or an insufficient Amperage 9V supply is used.

 

There was a recent thread discussing EU/UK 9VAC PSU options here: http://atariage.com/forums/topic/281972-replacement-psus/

and previous to that as well: http://atariage.com/forums/topic/221488-euro-power-supplies/

 

in summary

UK version 2.1A supply: https://www.amazon.co.uk/RockPower-Power-Supply-Great-Britain/dp/B00LLHKKZG/ref=lp_5440365031_1_6?srs=5440365031&ie=UTF8&qid=1534829848&sr=8-6

EU version 2.1A supply: https://www.amazon.de/dp/B00EA13U3E/ref=pe_386171_38075861_TE_item

Hard to find higher AMP 220/230V adapters currently, but 2.1A should be sufficient.

[repetto74]

Hard to find higher AMP 220/230V adapters currently, but 2.1A should be sufficient.

 

 

Is 2.1 amps sufficient? I read somewhere it would need more around 3 amps to be on the safe side and avoid PSU overheat.

 

EDIT : I have checked other users and there is this RockPower PSU at 2.1 amps which seems to work pretty good so I just ordered one :-). Just to wait a couple of days and I can start some T/S.

Edited August 31, 2018 by repetto74

[flashjazzcat]

1.3 amps are sufficient, we finally figured out. This figure is verified by current draw measured on an operational 1050. Therefore a 2A 9VAC PSU is an ideal choice for the 1050.

[Bikerbob]

I know this thread is old, but I am trying to reduce my foot print for 9v ac adapters. Anyone know either one large item I can pull multi lines from? or smaller that I could plug a row into a powerbar and be done?  

 

I am in Canada, so 110v. Thanks    the 31vac.. I assume is a measurement comparable to  DC AMPS?? there for the 2A 9VAC is ok??

 

James

[TGB1718]

The output 31VAC is equivalent to the wattage, so for the 9V output it would be around 3.4 Amps. (watts/volts)

 

A 9V 2A supply might work on a 1050, I think some people here have used them successfully,

but I would think they get rather hot.

My 1050 is 27VAC so it's a 3 Amp PSU

[Peri Noid]

1 hour ago, TGB1718 said:

A 9V 2A supply might work on a 1050, I think some people here have used them successfully,

but I would think they get rather hot.

If the main motor is in a good condition, 2A are enough. I make such PSUs for myself (and only myself) and there are no problems. But if the main motor is dusty and not clean inside, even a 3A (standard) PSU may be working at it's limit.

 

PS. Notice, that there is one more factor limiting the power - the 7812 and 7805 converters (the second one is not that important, though). 

[TGB1718]

Yes, I understand that 2A will probably do, but the general rule for all PSU's is it should

be running at between 65% to 70% of the rated capacity, you shouldn't really build a

2A PSU to run at 2A all day.

[TZJB]

19 hours ago, Peri Noid said:

If the main motor is in a good condition, 2A are enough. I make such PSUs for myself (and only myself) and there are no problems. But if the main motor is dusty and not clean inside, even a 3A (standard) PSU may be working at it's limit.

 

PS. Notice, that there is one more factor limiting the power - the 7812 and 7805 converters (the second one is not that important, though). 

 

I must have misunderstood? Nothing at all operates without the second one, not even the power LED. I think you meant the power consumption was less significant maybe?

 

7 hours ago, TGB1718 said:

Yes, I understand that 2A will probably do, but the general rule for all PSU's is it should

be running at between 65% to 70% of the rated capacity, you shouldn't really build a

2A PSU to run at 2A all day.

 

I agree. I wasn't a member when the first member made the topic, however Atari would have supplied a lower rated PSU if they could. All 1050 PSU should have a minimum rating of 9V 27VA as did the 810 (except early 810 pre-analog versions of 20VA).

 

However Atarimania's FAQ indicates a 50W supply!

 

https://www.atarimania.com/faq-atari-400-800-xl-xe-what-is-the-atari-1050-disk-drive_28.html

 

Atari 1050 Power Consumption
Standby: 1.5 watts (maximum)
Operating: 30 watts (maximum)
Start Up: 50 watts (maximum)

 

There are unfortunately many designed internal power losses in the 1050 which are dissipated as heat. Plus you will need any PSU overhead if a drive enhancement is fitted.

 

There are ways to mitigate the power losses, for instance many people have replaced the two voltage regulators for low loss Traco type equivalents, but this can sometimes bring it's own interference problems.

 

Currently this PSU is available on eBay:-https://www.ebay.com/itm/364048551176 or this:- https://www.ebay.com/itm/266631522886. There are similar choices available for part number Atari C017945 which seems to be the 110V 9VAC 31VA PSU. Interestingly the part number on the cardboard box of similar items seems to be CA017964 which is the part Atarimania quotes as 50W!

 

 

[Peri Noid]

21 minutes ago, TZJB said:

I think you meant the power consumption was less significant maybe?

Yes, this is what I meant. Not that important == it draws less power.

[Bikerbob]

Well I have lots of PSU.. my issue is ..if you have 6 of these plugged in.. they warm up the room pretty good.  Sigh.. oh well.

 

James

[TZJB]

3 hours ago, Bikerbob said:

Well I have lots of PSU.. my issue is ..if you have 6 of these plugged in.. they warm up the room pretty good.  Sigh.. oh well.

 

James

 

AC transformers are quite efficient. It's the DC power conversion that normally creates the heat. In the case of a 1050, the internal heatsink gets hot due to the voltage regulators and motor power transistor. But I see what you would like to achieve.