PC Engine CD drive requires warm up

[SignOfZeta]

Ok, after numerous tests I believe chop5 and I have narrowed this issue down to a few components.

I'll do a complete write up of the whole investigation later.  I still have a few more tests to do to try and narrow it down to one single component.  I need volunteers who have an issue exhibiting warm up symtoms!  I have a hypothesis that I need more data on to confirm.

I believe that the warm up issue originates in either the laser sled motor seizing up, or the middle gear becoming slightly damaged / deformed causing the sled gear train to lock up.  Or it could be both of these issues.  I have pretty much 100% confirmed this is NOT a motherboard issue though!

Anyone who wants to help out and has a warm up troubled unit, do me a favor... when it turns on but doesn't spin... pop it open and just touch the gear on the end of the laser sled motor to turn it just a bit (break it free perhaps)  and then try running the unit again and see if it fires right up or not.

Hmm... sounds a lot like what happens with my TurboGrafx CD.  I have to fight with it for several minutes before it decides to move the laser.  The cause: the f***ing middle gear.  That little pile of crappy plastic gets stuck on my TurboGrafx CD and only starts moving after I move the laser back and forth several times for 15 minutes or more.

Well, its like this. If your gear hasn't broken yet, then you don't need a new gear. You need to thoroughly clean the entire gear set and re-lubricate it. It will then be good for another 15+ years or so. The alternative is to just keep manhandling the crap out of it until it breaks, in which case then you'll need a new gear.

When diagnosing things its really important to not get overly hung up specific factors. Even if you install a brand new gear, you're still going to have problems if you don't get rid of the old grease and put some new stuff in there.

[chriscomputers]

Well my issues has nothing to do with the laser not moving. It moves freely upon start up no problem. It flat out just reads poorly for 3 to 5 minutes and then just starts working great. I never have to push the laser to get its movement  started.

[Ace]

Oh.  Well then, in that case, disregard what I've said.

[blueraven]

chop5 has been shipped 2 two units; one US (the warm-up unit BMW sent me) and one JP (The one Frankenstein that we concluded was a "dead motherboard") for testing. 

[BlueBMW]

Excellent blue!  I look forward to the results!

[chriscomputers]

Well, what do you know. I just fixed the problem. It was bad caps on my CD player. I just looked for the ones with some corrosion on the legs and replaced. Works great now. 

[BlueBMW]

I figured some of the units might be the victim of bad caps.. But I have replaced caps on units with warm up trouble and had no change.

[BLADES OF STEAL]

Well, what do you know. I just fixed the problem. It was bad caps on my CD player. I just looked for the ones with some corrosion on the legs and replaced. Works great now. 

     



Was this hard to do?

[BlueBMW]

Well, what do you know. I just fixed the problem. It was bad caps on my CD player. I just looked for the ones with some corrosion on the legs and replaced. Works great now. 

The hardest part is getting the motherboard out and in a position to replace the caps.  They're all through mount so they're much easier to remove and replace than surface mount caps.  Just be aware of clearance issues if you use higher voltage caps since they tend to be much larger.



Was this hard to do?

[chriscomputers]

It was not all that hard to do. I ended up using caps from a D-34 sony drive I had sitting around for parts. The only part I worried about is sometimes the ribbon cables for the lens itself can be very brittle but I got it back together just fine.

[chop5]

mine and bluebmw's findings so far with 3 warm up units. Thought at first it was one of the 2 motors had the brushings wearing off because they are way past there cutoff date but the more we explored we found the real culprit:

Bmw's warm up unit:
Had a unit where he did extensive cap and Ba chip change. We were doing a mechanism change when we thought it was a motor problem. Did the mechanism change and it worked right away where he did the famous youtube video showing it. But when he put his original mechanism and moved the middle gear with finger and unit would start up without warm up time. Our first clue to a possible gear problem.

blues unit:
first thing i noticed is the dial stays lit until it starts to spin. This is an indication of stuck laser but without the startup. So opened the unit and one of the gears has seized up. Slid the motor gear out slowly with a tiny flat head and sure enough it was the middle gear.
The motors gear moved freely and the sled gear is suspended on its own shaft so it cant get stuck. Went on a quest for lube and only found white lithium grease and graphite. Greasing the outside wont help as the friction is on the axel so i removed the small metal oring that holds the middle gear in place and slid the gear off. Cleaned its tiny axle with alcohol swab and no residue was found. Lubed up the axle and the inside of the gear with a toothpick with graphite first and still got friction from it so cleaned off the graphite and used lithium. I got slightly better results but noticed that the inside of the gear is very tight. I think its swelling over time and causing the friction on the axel which causes the motor to strip it. Swelling from age and plastic liquefaction which also causes the gears to loose strength,makes them soft and even easier for the motor to strip it.
But as soon as lube was applied no warm up time started up right away.

Can anyone recall if before their unit stripped its gears if the unit needed warm up time?

Ope'e unit:
Unit would not spin,gear intact sent to bmw for laser change. Laser change done but bmw noticed warm up time of 8 to 10 minutes. Sent back unit where some days later even tho with new lube on outside of gears ope heard the dreaded motor stripping noise and unit died. Sent to me and did a zombie gear change and unit came to life with no warm up reinforcing the seized up gear theory.

I'm pretty sure the warm up is connected to the problematic middle gear. The middle gear seizing up and the motor taking its time to free it. But since i get resistance even with lube i fear its only a band-aid. The gear will die eventually. It will die even quicker without some sort of lube on the axle so if your unit is having warm up issues STOP using it until you can get some lube in it.
Either do it yourself or send it to one of us.
I'm trying to find the perfect lube so far graphite and white lithium grease aren't doing well so im looking for some silicone and molybdenum and a better form of graphite. Perhaps a better lube will help or it may be just as good as it gets with the swelling.
The tests continue...

[Game-Tech.US]

Do you have access to a set of really small drill bits? I'm just wondering if reaming the hole back to correct size would help.

[SignOfZeta]

Do you have access to a set of really small drill bits? I'm just wondering if reaming the hole back to correct size would help.

That's what I was going to say.

I'm not really sold on the idea that the gear actually shrank. I think the real problem is that gears like this tend to be made out of plastics that are said to be "self lubricating". I think that shit dried out, which is why the gear is more brittle, and then it got stuck on the shaft. If you can drill the hole slightly larger though, and get some sort of lube in there, it might be the fix.

[chop5]

drilling will not be possible given the state of the gears. this is melting plastic syndrome!

but i took what you said and took out 3 dead gears i had laying around. They all show swollen symptoms and one actally cracked in half as i put back in the axle.  

I have a gear still attached to its mechanism and is still working and it is as fluid on the axle as can be so i don't think they were supposed to be like this or a design flaw. Friction is a bitch and will destroy whatever it touches over time.

funny thing about that still intact working gear,its turning clear. i think the previous owner added oil that seeped in it.

[chop5]

i think i found the perfect lube,silicone. I bought a tube off ebay,TRA1647 Silicon Grease by Traxxas made for remote control cars servo gears and stuff.
Tested for many days on blueravens consistant 20 minute warm up unit. Now turns on right away. That silicone is super slippery even when i was applying it with a toothpick to the inside of the gear and axle it was slipping around. I applied alot but not too much. No sign of absorption by the gear.
Unit is being return now so it can be played the shit out of. Unsure if later on more silicone would have to be applied.

So if anyone doing this you need to slide off the motor gear carefully with your fingernail and then remove the tiny O ring that holds the middle gear in place. I used a combination of tiny screwdriver,fingernail and needle to lift it off. The O ring has a split on it so it can be lifted. be very careful not to touch the gear directly it is fragile and could break. It is very tiny and easy to loose so do this in a clean flat area in case it flies off from the pressure.
Once removed clean the axle with a alcohol swab. If you can clean the inside of the gear with a twisted tissue made to size but again it can split if too much pressure is put or if the tissue is to big so if you leave it alone that will be fine.
Now lube with a toothpick over the axle and inside of gear and place back the O ring.
Voila.

If you cant do this i have a full tube of silicone so i can do it for you just pay shipping back