Atari 800 XL Humming Sound

[Zoober1016]

Hello,

I have an Atari 800 XL attached to a Taxan monitor using a composite video cable. When I power up the computer with a cartridge inserted, there is a humming or buzzing sound and no display on the monitor. I have tried holding down the Option key while powering up and this didn't make a difference. Since I don't have a spare monitor or Atari to try, I'm not sure which device is causing the problem. I have tried the TV switchbox on my TV, but there is still no display. However, this may be due to an incompatibilty problem. Has anyone come across this issue before and could offer troubleshooting suggestions? I'd appreciate any advice. I really enjoy playing the old time games and would like to get this working again. Thanks

[Rybags]

First up, try without a cartridge.

 

Secondly, buzzing is a symptom of a power supply that's gone bad and feeding too much voltage to the computer.

If that's the case, then it can fry the innards of the computer.

[Zoober1016]

First up, try without a cartridge.

 

Secondly, buzzing is a symptom of a power supply that's gone bad and feeding too much voltage to the computer.

If that's the case, then it can fry the innards of the computer.

 

 

Thanks, I will try that. The noise is actually more of a hum rather then a buzzing and I do have the power light illuminated. It would be nice to have a spare supply, but unfortunately I don't.

[zylon]

I had something similar happen with my 800xl. It turned out that 2 chips had failed. The second large one from the left, bottom row and the second one from top right corner.

[Rybags]

Hum or buzz... similar thing.

 

If you're running to a monitor using A/V cables then there should normally be no noise over audio.

 

I got a machine on eBay and the power supply is bad and generates audio hum - I've never used it again.

 

Running your Atari with it is very likely skating on thin ice. Can you post a pic of the power supply? There are known bad ones that are notorious, so we'll know right away if it's one of them.

[Zoober1016]

Hum or buzz... similar thing.

 

If you're running to a monitor using A/V cables then there should normally be no noise over audio.

 

I got a machine on eBay and the power supply is bad and generates audio hum - I've never used it again.

 

Running your Atari with it is very likely skating on thin ice. Can you post a pic of the power supply? There are known bad ones that are notorious, so we'll know right away if it's one of them.

 

 

An update to my problem: I discovered that if I disconnect the black audio cable on the back of the monitor, the hum disappears. Also, I can now see a display on the monitor, but it is just a bunch of lines. Do you think the Atari is OK and I just need to replace the monitor? I'd like to narrow down the problem to one or the other device?

[Rybags]

Why not try a TV via it's AV inputs?

 

If your TV doesn't have them, just use a video recorder on AV.

 

If you don't get a picture, then it's a fair chance that something's screwed... and I'd say it'd be a good chance that the power supply has caused it.

[Fox-1 / mnx]

An update to my problem: I discovered that if I disconnect the black audio cable on the back of the monitor, the hum disappears.

 

How surprising. Where's the hum supposed to come from if there's no connected audio input at all :-)

 

To me it just looks (sounds) like either your cable is broken or it's wired the wrong way. That hum may be one of the video signals plugged into the audio input of the monitor.

 

If the hum has an audio frequency of about 120HZ (US) or 100HZ (EUR) it's likely the power supply that is bad.

[atariksi]

Hum or buzz... similar thing.

 

If you're running to a monitor using A/V cables then there should normally be no noise over audio.

 

I got a machine on eBay and the power supply is bad and generates audio hum - I've never used it again.

 

Running your Atari with it is very likely skating on thin ice. Can you post a pic of the power supply? There are known bad ones that are notorious, so we'll know right away if it's one of them.

 

 

An update to my problem: I discovered that if I disconnect the black audio cable on the back of the monitor, the hum disappears. Also, I can now see a display on the monitor, but it is just a bunch of lines. Do you think the Atari is OK and I just need to replace the monitor? I'd like to narrow down the problem to one or the other device?

 

Besides cable being bad, it could also be grounding issues. I had an Amiga 1000 with the constant buzzing sound but the Amiga audio played fine but the buzz was the 5th voice. Just replacing the plug into another outlet fixed the problem. If your Atari audio is playing along with the buzz sound; i.e., the buzz is the 5th voice (or 6th) then try another outlet with better grounding or earth (the third pin on the plug).

[Zoober1016]

Hum or buzz... similar thing.

 

If you're running to a monitor using A/V cables then there should normally be no noise over audio.

 

I got a machine on eBay and the power supply is bad and generates audio hum - I've never used it again.

 

Running your Atari with it is very likely skating on thin ice. Can you post a pic of the power supply? There are known bad ones that are notorious, so we'll know right away if it's one of them.

 

 

Here is a picture of my power sipply. I'm new to this site so I hope I attached the file correctly. If you think the supply is bad, would I just need to replace this or could it have damaged my computer, too?

[+bob1200xl]

Wait a minute...

 

If you disconnect the black cable and the hum goes away, are you sure that is the audio cable? Some cables have funny connector colors. Try all the cables, one-at-a-time in the video port and see if one or more give you a good picture.

 

As far as the power supply goes, the big filter capacitor can go bad and you will get a lot of hum on audio. This will not harm your computer as long as the regulators are working. The power supply will just bounce up to 5 volts and then drop off at the line frequency.

 

Bob

 

 

 

Hum or buzz... similar thing.

 

If you're running to a monitor using A/V cables then there should normally be no noise over audio.

 

I got a machine on eBay and the power supply is bad and generates audio hum - I've never used it again.

 

Running your Atari with it is very likely skating on thin ice. Can you post a pic of the power supply? There are known bad ones that are notorious, so we'll know right away if it's one of them.

 

 

An update to my problem: I discovered that if I disconnect the black audio cable on the back of the monitor, the hum disappears. Also, I can now see a display on the monitor, but it is just a bunch of lines. Do you think the Atari is OK and I just need to replace the monitor? I'd like to narrow down the problem to one or the other device?

[dmlloyd]

Honestly the most common cause of this is that you have the video cable plugged into the audio input, and vice-versa...

[AtariNerd]

Sounds like you might have a Commodore a/v cable hooked up to your port. They look the same, but the pins are a bit different. It will work, but you'll have to experiment by swapping out each lead into each port. The thing about using cables for other systems though, is one isn't entirely certain if you're getting pure luma/chroma. I'm probably off, but don't some Atari's carry luma, chroma, a seperate mixed signalor two seperate luma channels? It's possible it might be mixing the luma and the composite and not pure seperated chrom/luma. The picture will be better than RF, but may not be optimum.

 

I'm sure some one will correct me.

[marquisor]

Could someone with a 100% working PS please list up the measured voltage at all pins?

I want to exclude possible errors with my 800 XLs because of faulty PSs

 

THX!!

[Rybags]

The PS is +5 Volts only.

 

I've got a good one and a suspect one. Good one measured around 5.08, suspect one was 5.2

[+orpheuswaking]

If I recall that's the power supply alleged to fail the most and take out 800xl's when it does... Although if it's about to die you should be getting wavy lines on the display. Definately check the PSU for +5 when mine failed it wouldn't hold a steady voltage and would read as high as 5.22

[Rybags]

There's a thread around somewhere that has the article with the common PS types and their chances of failing.

 

IIRC, the solid epoxy-filled "solid" ones tend to be bad... my good one's the vented trapezoid type, my suspect one's the later solid type.

[+orpheuswaking]

Actually, here is the info I was referencing. You have the version #3

 

http://www.myatari.com/ebay/psxl.jpg

 

Version #1(upper left), the White Brick, has a white top and dark brown bottom, 4" X 8" & 2 1/2" high. Version #1was shipped with early 600XL/800XL computers. Output 5 VDC at 1.5 Amp. Atari Part# C061982. Very reliable. Very Rare

 

Version #2(lower left), the Black Brick, is same shape and size as Version #1but all black, 4" X 8" & 2 1/2" high. Version #2 was shipped with later 600XL/800XL computers. Output 5 VDC at 1.5 Amp. Atari Part# C061982. Very reliable. Very Rare

 

Version #3(center top), the Ingot, is solid & all black, 3 1/4" X 5" & 2 1/2" high. It was shipped with most 600XL/800XL and some 65/130XE computers. Output 5 VDC at 1.5 Amp. Atari Part# C061982. If hum bars are seen on the screen disconnect version #3 power packs. Not recommended for unattended operations.

 

Version #4(top right), the Box, is slightly smaller than the Ver #3 at 3" X 4 1/2" & 2 1/2" high. It was shipped with most 130XE computers. Output 5 VDC at 1.5 Amp. Atari Part# C061982 Very reliable. Getting hard to find. We recommend this version for all 130XE and 800XL computers especially for 24/7 operations. Plenty of power for add on such as MIO.

 

Version #5(bottom center), the Mini, is the smallest at 2" X 3" & 2" high. It was shipped with most XE Game Systems. Output 5 VDC at 1 Amp. Atari Part# C70042-011. Not as rugged as version #6. For continuous operation use #6 for a 1Amp instead of #5.

 

Version #6(bottom right), the Logo, is the same size as Ver #4, 3" X 4 1/2" & 2 1/2" high but has an Atari Logo molded into the case. It was shipped with most 65XE computers and later XE Game Systems. Output 5 VDC at 1 Amp. Atari Part# C70042-01 Very reliable. Works great in most applications. Not recommended on machines with aftermarket memory upgrades or MIO expansions.

 

 

[marquisor]

The PS is +5 Volts only.

 

I've got a good one and a suspect one. Good one measured around 5.08, suspect one was 5.2

 

Ok, here's what I've got:

 

newer PS: 5.20V

newer PS: 5.26V

older PS: 5.15V

 

the newer ones are similar to the one on the pic posted here some posts ago, the older one the bigger with open vent slots

[lbaeza]

Here's the Best Electronics PSU guide:

 

http://www.best-electronics-ca.com/power%20guide.htm

 

Regards

[Rybags]

In theory you might well get some voltage drop once the thing's put under load.

 

But on the other hand, I know for sure that the "suspect" one I have causes the machine to buzz, so I never use it.

[+bob1200xl]

It may be useful to also measure the AC voltage on the supply. It should be less than 100mv, or so. The AC component is the source of noise in the audio and black horizontal bars on the video.

 

Bob

 

 

 

The PS is +5 Volts only.

 

I've got a good one and a suspect one. Good one measured around 5.08, suspect one was 5.2

 

Ok, here's what I've got:

 

newer PS: 5.20V

newer PS: 5.26V

older PS: 5.15V

 

the newer ones are similar to the one on the pic posted here some posts ago, the older one the bigger with open vent slots

[Paul Lambert]

Eleven years later. I just got a "new" Atari 800 XL which I have connected with a SCART cable and I am getting a hum as well. I new power unit is coming soon, so when it comes, if the sound disappears I will know that it is the old power unit that is bad, right? I don't want to fry my Atari 800 XL now that I just got it.

 

Of course, if anyone here is familiar with such problems coming from SCART, I would appreciate your comments.

[archeocomp]

If your Atari is working and your power supply is not an ingot type and you checked voltage to be 5.1v max then you may have cable/grounding problem. Otherwise get good PS, before you continue.

[Mclaneinc]

The ingot is smooth and has an extruded shape like a pyramid (but not so narrow) tapering off with no point on it, as said, like a pyramid with the middle to the top cut of and flat..