Eumig 800 HQS amplifier problem and solution

[Erik Snel]

Hi all, Yesterday i got a Eumig Mark S810 HQS for my collection and its amplifier wasn't working. Now i allready have some 800 projectors with an HQS amplifier and some are broken and some are not. Mind you, they are different in comparison to a "normal"800 series amplifier. I had a suspicion which turned out to be true. The HQS amplifiers have a big capacitor 2200uF, 40 volts. It is switched paralel to the diode rectifier to make sure the rectified power becomes as much of a DC as possible with the least amount of ripple (i dont know the correct english terms but electro technicians will know what i mean, it is a very common way of rectifying AC to DC). Anyway Capacitor C30 will short out after years and kill the fuse of the amp immediately. I have a circuit diagram but if you open the projector up the big capacitor cant miss. In a normal 800 amplifier this capacitor is switched differently and poses less of a problem.

So the first thing i did was getting rid of the capacitor to test the amplifier and lo and behold, it worked again. Mind you the power is not rectified to a good DC so you will hear really weird sound coming out of the speaker. But for diagnosing it is fine. So the solution as with so many old pieces of electronics, when this happens it needs new capacitors. So if you are wondering if the sound heads are dead, which is a big fear with eumig owners. It might be just the capacitors. It takes an afternoon of work and maybe ten euros for new capacitors and a box of fuses.

In 20 years of playing with eumigs i never had one with dead sound heads, because the 100 hours they where guaranteed with are seldom reached in the days of normal use.

the caps i am going to replace : i will replace them all just to be sure

- 2200 uF 40Volts
- 1000 uF 16Volts
- 47 uF 25 volts
- 4 uF 16 volts

i hope this helps saving more eumigs from unneeded disposal

[Leonard Goss]

Great tip Erik, thank you for posting it and best wishes.

[Phil Murat]

High Erik,

Modern components are much smaller now than there was 40 years ago and showing same features.

So, I suggest you to go a bit higher for Voltage limit , Exemple :

2200µF / 40 v => 2200µF / 63V
1000µF / 16V => 1000µF / 25V
Etc, Etc......

Prefer 105°C limit instead of 85°C

Best Regards
Phil

[Erik Snel]

yes that would not be a problem, i just write down what i find and my electronics shop never has exactly the same, so indeed most of the new ones i get have a higher voltage limit. ans sometimes you have to fiddel to get the wires fitte because indeed modern components are smaller. this depends on what the local electronics shop has in stock, if you are lucky enough to have such a shop in town.

[Phil Murat]

I avoid to buy Capacitors in Shops in town, sometime their stock is too much old.......

[Paul Browning]

I use a peak tester for these passive components, esr tester. This has proved invaluable to determine even new components are up to scratch. If a cap is shorted it will take out a fuse, but some go high resistance, this tester will test this accurately and may save you buying new one's. A very good range of tester and a good little book comes with them too, plus you learn a lot at your own pace.

[Steve Klare]

I always go to internet distributors these days, they have a tremendous variety of parts and they rotate them through stock pretty quickly. Then again, since Radio Shack went under it's not like I have much of a choice.

I replaced the big cap in my own Eumig 800 years ago: the hum was...more than I needed, so I figured the cap had to be dead. I was able to go from 2200uF up to 2700uF or even higher in the same package with a higher voltage rating too.

If it did help the hum, it wasn't enough for the difference to be stunning. Especially given that when I put the old cap on a capacitance bridge it was dead-on.

It's just a hummy machine: I think the head is too close to the power transformer and it's picking up stray fields. It's still a good one, though. It's kind to film and it's never given me any trouble in 18 years.

[Alan Rik]

I replaced the big cap in my own Eumig 800 years ago

How old are you Steve? That’s a long time!

[Steve Klare]

Wow! -and that’s why we have punctuation!

”Let’s eat, Grandma!”

vs.

“Let’s eat Grandma!”

[Erik Snel]

Here we go, new caps and it plays fine again!!! I also have a 824 Sonomatic HQS with the same problem so i recapped it to. problem solved (took me 7 years to find out for that one )

[Paul Adsett]

Great post Erik. Can you place it in the Index of Technical Topics sticky at the top of the 8mm forum page. Just reference it in a post there and Doug will put it into the Eumig section.

[Douglas Meltzer]

Paul,
I've just updated the index.

Erik,
Thank you for this topic!

Doug

[Lee Mannering]

I'm rather enjoying watching someone younger else pick up the Eumig baton Well done Eric. Some of the old hands (not so old) on here will have had years of me enthusing about the humble Eumig sound projector although my greatest love with film equipment is the intermittent itself.
50 years down the line I still enjoy a show with a Eumig projector and they have proven very reliable for me and I have many.

Talking of sound I fitted a analogue to digital optical block inside a 810D which eliminates most of the vintage amplifier then plugs into my AV amp. The sound is improved somewhat.

[Erik Snel]

I started playing with projectors very young, i was thirteen in the year 2000. (eumig mark 607D) so i allready do have quite some years of experience but when i started 8mm was already considered dead. lucky for the modern internet it is still very much alive (again). the only downside is that there are not many people my age (twenty years ago and now) who like this hobby to. so i dont have many people to share it with but that is where the internet again is very handy to meet likeminded people. I hope to play around with these machines for a very long time to come

[Erik Snel]

funny thing, today i go a Eumig Mark S812, which is a very rare type of number. for some reason the serial number index sais its a S810 which is correct as for the functions but is it silver grey instead of black and white. but also this one has a shorted out capacitor. and some other fun things but as soon as i have it playing im gonna make a new post about it.