Build Your Own Arcade Controls Forum

Arcade Collecting => Merit/JVL Touchscreen => Topic started by: DaddyLongLegs on January 09, 2017, 04:37:43 pm

Title: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: DaddyLongLegs on January 09, 2017, 04:37:43 pm
Hello! A few months back you fine folks walked me through getting my upright Megatouch XL to work. Back then it was the chip on the i/o board that has DOS stored on it (the chip rotted somehow). I bought a new motherboard and I/O board on eBay and after getting help making this thing work with CF instead of CD-ROM, all was well.

That lasted a whopping 3 months or so. I went to put the thing on 2 weeks ago and it will not boot. When I power it on, all I hear is repeated sounds from the speaker that sound like the machine is powering on and off at a very fast rate (seriously it's like every half second).

There were a few times (maybe 4 out of 100?) that I got it to boot. Those rare times I either got an error about missing some driver file (this is from FREEDOS installed to the CF) or I will get really, really lucky and I will see the Megatouch splash screen but it lists zero games and all I can do is see the Megatouch advertisement splash screens for other exciting products.

So I bought a brand new Megatouch power supply. I got it in the mail the other day and finally had time to wire it up today and....same thing! So it is not the power supply, somehow.

I also do not think it is the motherboard because I have two of them and they both give me the same results. Though I did have two I/O boards at one point, unfortunately I gave one away so I only have one to test. Though I can't imagine it's the I/O board since this one looks brand new practically.

List of things I have tried: different sticks of RAM, taking out the CMOS battery, different ribbon cable for the CD-ROM/CF, new power supply, different motherboard, different sticks of RAM, and taking out the riser board and plugging the i/o board directly into the motherboard.

If I take out the i/o board I get no booting either. The only difference is I don't hear the sounds from the speaker when it constantly reboots. I have tried taking out the RAM and leaving the i/o board in and the same thing happens so I don't think it can be the RAM.

I am at a loss trying to think about what else I could possibly do. I can't believe what a nightmare/curse this thing has been to me. I don't think I have ever had this amount of trouble with any piece of tech in my life. Any advice on what to try would be greatly appreciated!
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: lilshawn on January 10, 2017, 12:20:20 am
sounds like it's in overload protection. does the voltage from the power supply jump up and down?

check the riser board. make sure it's plugged in properly and seated all the way down. also try removing the riser and see if it will boot.

double check your power supply voltage (particularly the 5 volt rail (red wires) and make sure they aren't low) even a new power supply can be weird.

when in doubt.. remove everything and power up the board on the bench with just a monitor connected. then slowly add items and see if something causes it to do the bootloop thing.

if just the bare board with nothing plugged in doesn't work... maybe you have bad caps on it causing the overload to trip on the power supply.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: obcd on January 10, 2017, 03:27:29 am
Same advice here. Try to run the mobo with just a monitor connected. (Without io card and disk and without touchscreen connected.)

It should show you the initial bootup screen and some message that it can't locate a boot device.

It's pretty normal that you don't hear anything with the io card removed.
The sound chip and sound amplifiers are on that io board. The speaker is connected to that board as well.

It's also a sort of behavour you can get when the cmos backup battery is running out. Have you checked the CR2032 on the motherboard? (If you have one) Sometimes those older mobo's use a chip with integrated battery (big square black block)
I checked my spare megatouch xl board and it's having a cr2032 battery.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: DaddyLongLegs on January 10, 2017, 08:51:05 am
Thanks for the replies. The CMOS battery is definitely fine; I should have mentioned I bought a new one and replaced it. As for the monitor, can I use the Megatouch monitor or does it have to be a different VGA monitor? I am only asking because I have never once in my life got this machine to display an image if the i/o board wasn't plugged in.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: obcd on January 10, 2017, 09:13:32 am
It might be better to use another monitor in that case. Those old pc's use a 640 x 350 EGA resolution for their boot screen.
The game switches that resolution to 640 x 480. Maybe your original monitor is unable to display the 640 x 350.
When it worked, did you see the boot sequence with text before it shows the megatouch splash screen?
I believe you did as you took several pictures from it during the transfer to compact flash.
In that case, it's strange that it's not showing you anything without the io board. There is nothing essential on that io board that is needed to boot.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: DaddyLongLegs on January 10, 2017, 10:54:14 am
Wow, that really is weird. Especially since I have two motherboards to test!
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: obcd on January 11, 2017, 03:19:03 am
In fact, it's so weird that I decided to try it out myself.

Initially, it wasn't giving me a picture either, so I installed the io card.

Bingo... Got a boot screen..

Now, the funny part.. I removed the io card again and... It still boots without it. (Expected behavour)

Isn't technology wonderfull?

No idea why it wouldn't boot the first time.
It has been in storage for several years with the battery removed...
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: DaddyLongLegs on January 12, 2017, 06:21:57 pm
Well I determined on the 2nd motherboard that the riser card definitely isn't helping. It's a BRAND NEW riser board which is crazy. I had an older one that I cleaned like crazy and I still have the same results.

Luckily I can plug the io board directly in because I have an upright and everything will still fit. But people with bartops would be screwed as they would have to use the riser board.

I guess I can just leave it directly plugged in but I am wondering if that is what ruined my other motherboard (me moving the cabinet across the room with it plugged in directly. Maybe the io board wobbling permanently ruined the slot on the motherboard?)

I would directly solder the damn io board to the motherboard if it wasn't going to be a million wires!
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: mahkeymike on January 13, 2017, 12:44:31 pm
did you try cleaning the contacts with a eraser and also use some 220 grit sandpapper to slide into the ISA slot on the mobo? you might want to wrap the sandpaper around something like a credit card so it gently makes contact with the pins in the slot. Be careful not to side to side. Only straight up and down motion.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: lilshawn on January 13, 2017, 12:49:04 pm
does that riser board have some capacitors on them? in particular tantalum capacitors where pretty popular around that time.. they often fail shorted...even for no reason.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: obcd on January 13, 2017, 06:09:52 pm
So, if I understand correctly, with the io board directly plugged into the motherboard it works?
With the riser card plugged into the motherboard and the io board in the riser card, it's not working?

To my knowledge, there are no capacitors on that riser board. (2 lazy to check it out now)

Maybe 2 contacts of one of the riser card connectors are touching each other?

Or maybe, the connections between the mobo and the io board becomes 2 long.
If one of the address or data line buffers is on it's way out, this could happen.

And yes, I have had problems with such isa cards (in a temporary setup)
When the card wasn't perfect vertically in the connector, things didn't work properly anymore.
So you should somehow provide a fixation for the io board if you intend to use it without the riser card.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: DaddyLongLegs on January 13, 2017, 06:41:09 pm
did you try cleaning the contacts with a eraser and also use some 220 grit sandpapper to slide into the ISA slot on the mobo? you might want to wrap the sandpaper around something like a credit card so it gently makes contact with the pins in the slot. Be careful not to side to side. Only straight up and down motion.

I will try cleaning it but honestly I think this riser is brand new (I bought it with a new motherboard and IO card).

does that riser board have some capacitors on them? in particular tantalum capacitors where pretty popular around that time.. they often fail shorted...even for no reason.

There appears to be one of those small orange capacitors that say "103" on them.

So you should somehow provide a fixation for the io board if you intend to use it without the riser card.

If anyone has any ideas on how to do that, I am all ears! I thought about things I could do but came up blank.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: truckerbob on January 14, 2017, 08:47:22 am
My "Google-fu" is weak today, but earlier this week, I saw images of a setup like this, and they made brackets (braces) that went diagonally from the standoff bolt holes on the I/O board to the mounting points on the top of the motherboard. I'll search more tonight, and see if I can find a pic.
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: DaddyLongLegs on January 14, 2017, 06:30:13 pm
My "Google-fu" is weak today, but earlier this week, I saw images of a setup like this, and they made brackets (braces) that went diagonally from the standoff bolt holes on the I/O board to the mounting points on the top of the motherboard. I'll search more tonight, and see if I can find a pic.

Thanks so much. I would love to see that. Interesting that someone else had the idea.

I am wondering if I somehow ruined my old motherboard by moving my Megatouch with the i/o board plugged directly in!
Title: Re: Megatouch XL upright bootloops every half second; tried new PSU, mobo, and RAM
Post by: truckerbob on January 15, 2017, 11:02:24 am
I stand corrected.  After a lot of searching, I found the pic I was looking for, and it wasn't what I explained to you.  The supports I saw were from the motherboard to the riser.... so that isn't going to help you at all.