4000E Power Supply from 220 to 110

[Tonemiester]

Hello,
Does anybody have the jumper matrix to change a 4000E PS from 220v to 120v? I have the 4000G matrix but they changed to numbers from letters.

Thanks.

[amillar]

I'm confused, they were always shown as letters in the manual? (Whether E or G - the supplies are identical.) If you post a photo of the connector which the links are on I can explain how to do it - it's been 30-odd years since I last saw one so can't quite remember what it looks like!

Cheers, Andy

[Tonemiester]

Andy,
Thanks for the reply. I have attached a picture (not great). The jumper positions are lettered. The G service manual shows the same terminal block but with numbers instaed letters. Like you said, I'm sure the positions are the same. Any help would be great.

Mike.

[amillar]

Very odd - I certainly didn't change it, and my G series manual showns letters, maybe the 8K people changed it???

Anyway, here you are - I've double checked it twice to make sure I didn't mis-type any of this since I don;t want to blow you up!!!

Cheers,

Andy


100V  C to E   C to J   B to F   B to K

110V  C to E   C to J   B to G   B to L

120V  C to E   C to J   B to H   B to M

200V  C to E   F to J   B to K

210V  C to E   F to J   B to L

220V  C to E   G to J   B to L

230V  C to E   H to J   B to L

240V  C to E   H to J   B to M

[Tonemiester]

Andy,
Fantastic! Thanks for the quick reply. Ironically, the Service Manual I am referencing is titled 4000G and the section I'm looking at is titled 4000E Power supply. I have attached a copy of the page for you to look at. Weird. Thanks again!

Mike

[Tonemiester]

Also, I forgot to ask; I have voltage regulators labelled on the transformers:

250V
-20V
48V
7V

The 250V was in the +20V slot. All of the regulator cards look the same. Does it matter where they are located?

Thanks,

[amillar]

Hi Mike,

Ah...I see that circuit diagram was drawn in 1993, that's why I didn't know about it (that's just as I left). Probably the 8k team redesigned the terminal strip, maybe the old one went obsolete or it was for an electrical safety reason?

Really good question re the regulator cards ('98 cards). They ARE all the same, the reason they are  labelled is because if the PSU is adjusted with the regulators in particular slots, and then they are swapped around, component tolerances will mean that the setup will then be a bit wrong. So either in your PSU they were swapped and no-one checked, or they were swapped and re-adjusted in which case swapping them back will make slightly wrong again. Best thing to do is just to set the voltages back up again anyway. (Horrible job, I used to hate doing it, even with a special long insulated screwdriver.)

Cheers,

Andy

[Tonemiester]

Andy,
OK, re Regulator Cards, I assumed I was going to have to re-calibrate the voltages anyway. This has to be done under load I assume? And where on the 651 is a good place to adjust the =/- 18.5volts? I'm glad I kept my plastic tweekers from my tape machines. Thanks again. You have been a great help!

Thanks,

[amillar]

Hi Mike,

Fortunately I've only just sorted this for someone on another thread so I've cut and paste the answer below.

So have you got a 4k desk in Denver Co.? I might be going that way next year (I've got family in Fort Collins who've been trying to get us to visit them for years, and it does look to be a nice place.)

Cheers,

Andy

This is how I used to do it on the 651 (from memory):
Measure on the edge connectors of the '33 and '34 cards on the 651 backplane.

Starting with the '34 card (nearest the meter bridge). The last pins 53, 54, and 55 are 0V and are very obviously joined together - this gives you a reference point.

From pin 52 to 55 should be between -18 and -18.5V
From pin 51 to 55 should be between +18 and +18.5V
From pin 51 to 49 should be 7V - as near as you can get it

Now moving to the next card, the '33 card
From pin 47 to 55 should be +48V - somewhere between 47 and 49V.

Be careful - it is easy to get your meter probe to short circuit pins 52 and 53, or 51 and 52.

Wherever you measure it, do NOT measure and adjust between the 11V and 0V connections, ALWAYS measure and adjust between +18V and +11V to be 7V.

[Tonemiester]

Andy,
Thanks so much for that info and the quick response. however, before I can do the calibrations, I have to get +20v and 13v working. +20v has a red light and 13V has a yellow. +48 has a red light as well but I am not as concerned about that at the moment.

Thanks,

[brewery]

those leds will never change color, they are only there to show that the rails are not down.

hate to be that guy, but PLEASE be carful in there, these things can potentially kill you. don't adjust any other pots than the output voltage, and if you did by accident, have an experienced tech align the whole supply. you will need a very long flathead screwdriver, isolated with heatshrink, to get to the pots.

[amillar]

Well said!!!!!!! I used to work with those things all the time and they always scared me rigid.

Horrible, horrible design. But because every year from 1984 onwards was "the last year we'll ever make 4000s" we never got the funding to redesign it.

[Tonemiester]

Yes, I am so used to multicolor LED's that I just assumed that's what they were until I turned it off. Actually, this PS does not scare me at all. One of the easier ones that I have worked on. (try a 70's API 2488). thanks for all the help here!

Mike