Yamaha EL-90 freezes while booting - hangs on "Electone" screen

[vgb14]

We have an EL-90 that just started freezing on the 2nd screen that displays at startup, which is the "Electone" screen.

I observed that if the organ is off for an extended period of time, on the first boot attempt it sometimes gets to the third (menu) screen, at which point it freezes.

I can enter the Diagnostic using the C# chord sequence only if the organ has been off for a while, and it works long enough for the RAM to check OK, before it freezes.

The power-on reset operation using the upper left menu button doesn't appear to have an effect.

I removed the ROM cards and re-seated them. Interestingly the 1st time I did this, the organ booted and I was able to play some notes for 5-10 seconds before it froze again.

I also inspected the PU board and the caps and board look very clean.

I'm interested in knowing what you all think and if anyone has experienced this issue.

Thank you for your help.

[andyg]

We are seeing lots of reports of the caps on the PSU board failing, perhaps not too obviously, and eating into the tracks on the board. And there are issues with the connectors from that board. Even if it is not the cause of the problem here, you will very soon need to re-cap, judging by what's happening to other EL90s. So changing the caps and repairing any connector issues is a job worth doing as preventative maintenance. Not expensive and it sounds like you have the knowledge and skills to do the job OK.

Other routine things include unplugging, cleaning and reseating every internal connector and reseating any plug in boards, checking the motherboard(s) for any issues with bad joints, cracked tracks etc.

[vgb14]

Thank you for the tips, Andrew. I will follow your advice and update my progress in this thread. I've already ordered a few caps for the PU.

[tucsondave]

First make sure power supply voltages are correct.

Check around the bases of surface mount electrolytic capacitors on the DM board for green or black stains. Check DM board for "fishy" odor.

td

[orgfred65]

I have no special knowledge of EL90s, but for the computers that I repair, the electrolytic caps do dry out with usage. This can cause the electrolyte to warm up, and the top of the can therefore bulges, and ultimately can split. I have never seen caps inside computers that leak on to the board. So in addition to looking at the PCB for damage, do check the tops of the caps for any hint of bulging. Sometimes this fault can keep power voltages at correct levels until they are under load, which can make voltage measurements confusing.

[andyg]

Trust me, orgfred65, they do leak onto the boards. I think if you look around some of the several threads on EL90 power supply issues, there are some photos of the damage and the repairs needed. I've not seen a cap in an EL90 that's bulged, but it's entirely possible!

[vgb14]

The EL-90 is Alive!

Here are the steps I took: I have an Electrical Engineer friend who looked at the PU board schematic and determined the capacitors most likely to cause the kind of issue I was having. Rather than replacing all 48 capacitors on the PU board, he suggested first replacing the caps responsible for the low voltages for logic, with the understanding that even if it didn't cure the issue, it was a good idea to replace them anyway due to their age. The old capacitors had 1991 date codes on them. Here are the capacitors we targeted:

c212, c213, c214. 10000uF/10V
c215, c216. 220uF/10V
c221, c218. 100uF/16V

He did me a favor and soldered them in for me and it improved things to the point where the organ would boot to the third screen and you could actually play the keys for about a minute before it would hang.

So I proceeded to remove all the DM board's heat shields as per tuscondave's suggestion to search there for leaking caps, and I found one cap with a mound of powder under it. It was C161, 220uF, 6.3V. I removed it and soldered in a new 220uF 10V capacitor. Luckily, the residue was dry and cleaned up easily with some denatured alcohol.

The organ now plays as good as ever.

Many thanks to all the members here for their suggestions.

[pieanoman]

A friendly word of advice: the other caps will likely die too, and when they do, you run the risk of acid damage to the lower side of the PCB, just as Andy has noted above. You would be wise to replace all of them on the PU board. You can order them all from DigiKey for about $50. I can send you a list of the capacitors you need (I did the repair on my EL-87 recently)--just ask. Better to fix it now and know you don't need to worry for another 20 years, if at all possible. Enjoy your EL-90. Great machine!

[andyg]

Glad to hear that it's working fine again!

I'm not normally one to recommend wholesale replacement of e-caps unless we're talking a real oldie from the 50s or 60s that's never been touched (and even then my 1969 Hammond T's PSU and amp caps were all checked and came up fine, so were left as they were) but in the case of the EL series, this is becoming a very regular issue, for whatever reason (Yamaha are normally rock solid and much older organs seem to be OK.) I would definitely recommend changing all the caps as pieaonoman suggests above. Personal experience with the EL90s belong to friends and students tells me that even when the problem has been 'fixed' once, any non changed caps may well fail - in one case about a fortnight later. The caps are cheap enough - one student bought a bulk load from a supplier in the UK and shared them with friends, splitting the cost! An afternoon or two's fun with the soldering iron and all the ELs were singing nicely and should carry on for years now.

[Hammond-Organist]

I know if I still had my EL90 I would by now be changing all the Caps to preserve a wonderful instrument.

[auronoxe]

A little off topic: I really think it is great how „old“ organs are valued here by the fans of these machines and lots of effort and time is invested to get them going again. A few days ago I read an article about Amazon transporting fully functional technical equipment (like e.g. refridgerators) that was send back by customers a few days after purchase to the waste dump, just because it is cheaper than checking their funtionality and doing some repackaging. Isn‘t that crazy? Or are we crazy not to throw away an organ when it needs a repair after 20, 30, 40 years?

[andyg]

I don't think the manufacturers ever thought that their products would still be in use so many years later. A ten year old fridge or freezer is a rarity these days (though mine are that old and hanging on in there!), none of my washing machines (apart from my first Zanussi that did twelve years) has ever gone past five years and the last one only did three before becoming uneconomical to repair. A five year old phone is so much junk and so on. But a thirty year old organ running sweetly is much more common!

[Hammond-Organist]

For me if you love something enough you'll keep it going. One of my Motion Picture Movie Projectors is fast approaching 100 years of age in a few years, yes its a labour of love keeping it going but also gives me and others great pleasure. The size of the motor starter cap in these old girls is something to behold nearly a brick size and when the leak oh boy... Its special to project a silent film and play the organ for it at home something we have done for a very long time whilst the projector turns over another passion of mine. We did have an incident where a capacitor exploded in a machine during a show which lit up the room as everyone jump up simultaneously but the machine still kept going, funny when I look back at some of my capers.

Our Church has a couple of tone wheel Hammonds in it all turning over nicely also a digital piano which has been nothing but trouble, another up the road has a C3 played a couple of times a week which is really nice to have a go at from time to time after being presented with a key.

[vgb14]

Sounds like there's a clear consensus, so I will change them all in the near future. Thanks for the advice.

[seamaster]

The difference is they’re still making new fridges.