John's Arcade Forum - Classic Arcade and Pinball Collecting and Restoring Discussion Forum - RETRO MAME - Nintendo Vs Forum

So I traded a game for a Frogger Cocktail. The guy said it needed some work and he believed it may be the monitor. The monitor is 100v. I would like to plug it up and see what happens, but are there any precautions I should take beforehand?

Here are some pics of the inside.

(http://i1299.photobucket.com/albums/ag79/xcaliber95/DSCF0744_zpsb53e0558.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/DSCF0744_zpsb53e0558.jpg.html)
(http://i1299.photobucket.com/albums/ag79/xcaliber95/DSCF0741_zps862a8810.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/DSCF0741_zps862a8810.jpg.html)
(http://i1299.photobucket.com/albums/ag79/xcaliber95/DSCF0739_zps1c46b973.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/DSCF0739_zps1c46b973.jpg.html)

I turned the game on and I can coin up, but there is no picture on the screen. There is a crazy buzzing noise and no picture. I have sound and the game responds to the controls. I'm binging the hell out this, but I haven't found anything on 100v monitors yet.

If the monitor is truly a 100V monitor (which one is it? sanyo?) you need to make sure the isolation transformer is also a stepdown to 100V. under no condition can you plug this into your wall, you will damage the monitor and hurt yourself if you touch it.

Most isolation transformers are not exactly a 1:1 ratio, so hook up one side to your household voltage (120v ish) and measure the other side. If the voltage is higher, flip the isolation transformer around and check it again. I have a few transformers and generally with 120v in I get 110v out, that is close enough to 100v to make the monitor function properly.

it looks like it already has the transformer installed, so as long as you connect to it properly you will be fine to give it a try but probably nothing will happen if the monitor is bad. Without seeing the PCB for the monitor I have no idea which it is. Once you know what monitor it is we can work on fixing it.

Ian and Darkstar,

Here is a pic of the tube ( I'm finally able to identify some components correctly Ian, LOL). I know it may not help since it is not the monitor PCB, but I thought I would throw it out there. The number is S-97335-P. I did find a thread that was on this forum that covered a similar issue. I have checked the fuses that are by the transformer and the one on the PCB, they all check out ok. If you guys can't identify the monitor by the tube I will pull the monitor.

DarkStar,

I have tested a switching power supply, but never a transformer. Would you mind telling me what contacts to test?

(http://i1299.photobucket.com/albums/ag79/xcaliber95/WP_20150202_002_zpsda02c75e.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/WP_20150202_002_zpsda02c75e.jpg.html)

If you look at page 86 in this manual http://www.arcade-museum.com/manuals-videogames/F/Frogger.pdf you will see the wiring diagram for the cabinet. over on the left side you will see what is labeled 150 xfmr, that is the isolation transformer. There is a 115V tap that goes to the wall plug and then on the other side there is a 100V tap that goes to the monitor and a 115 tap that goes to the marquee light (which may not be in the cocktail)

If you put your multimeter on AC mode you should be able to measure the voltage at any point on the tap.  but remember that you will need to measure it with the black lead on what the manual calls 0V for either side. Most likely the transformer is completely fine and the monitor blew a fuse. Have you tried to plug the whole cocktail in and see if the game will coin up?

The game will coin up and play, but no screen. There is no tube glow either.

Yeah it probably blew a fuse. Time for a monitor repair!

Which one do you think it is? I could only find four of them and they all checked out ok.

Its going to be on the monitor im sure. You will have to remove the monitor from the cab to take a peak at it.

I will check it out. When you say monitor repair, does it need a cap kit or something more serious, or both

probably both.

Well I just got my solder iron today so now it is time for a cap kit and whatever else I need

well, pull the monitor out and sit it up on a table. take the PCB out of it by discharging the monitor and removing everything attached to the PCB so you can get the PCB out onto the table. Watch john's videos for that information.
I haven't looked at the schematic to see what is what yet but these are just general information for troubleshooting.


you'll want to try to identify fuses and large transistors, they will either be 3 pin large black things standing upright or round metal cans mounted on a piece of metal or the frame of the monitor. Check the fuses with resistance or continuity tests. For the big transistors you will want to remove them from the circuit board and test them using diode mode to see if there are any shorts. I believe john has a video on this as well, the tempest monitor repair video if i remember correctly.  If everything is good then we will have to look closer.

I discharged the monitor and got it out. I went to check a fuse on the PCB and felt a tingle. There is a large capacitor that I think shocked me a little bit. Do you think I did something wrong with the discharge? I didn't really hear anything, but when I place the screwdriver near the hole in the tube nothing! 

there was probably still 200V on the input cap. usually they self discharge but maybe that monitor doesn't have a discharge resistor. If you did something wrong you would be on your ass wondering how you lived.

Thanks for all the help so far Ian! I will tell my wife that if something goes awry to give you some of the life insurance money or at least buy a cap kit from you and finish the job. I remember John saying that the caps sometimes leak. There is some clear caulk like material around the cap. Also, if that cap hasn't discharged all the way how do I get it to discharge?

The white gunk or sometimes clear is probably hot glue that was installed when they built the monitor, it is there to hold the very large caps and keep them from breaking off the PCB. The caps can leak though and its usually a orange color if its been leaking for a while.

As far as trying to discharge the cap, just be careful not to touch the bottom of the board and when you get the board safely out, look at the caps and with a wire or better yet, a resistor, short the pins of the big caps together

Ian,

I can't find any numbers on the chassis that would identify the monitor. Only the numbers on the back of the tube.

I finally got around to checking the last fuse. It was beside the large cap that buzzed me. You were right, it was indeed blown. It is a 3/4A 250v fuse. I plan to assemble the cocktail in the morning. It is currently in pieces. I spent most of the day taking it apart to clean it. Once it is put together I will check the AC as you suggested.

Well the first thing you will need to do is check the input diode bridge for shorts.  I know that is pretty light on details but I can't look up anything right now. Then if the diodes are fine try to find big transistors and check them for shorts

So I got the cap kit for the monitor (Sega MC-2000S). As I was looking over what needs to be replaced I saw these that didn't match the ones I got in the pack. Can C523 and C503 be replaced with "standard" capacitors?

(http://i1299.photobucket.com/albums/ag79/xcaliber95/WP_20150322_002_zpsaf4qfj8a.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/WP_20150322_002_zpsaf4qfj8a.jpg.html)

(http://i1299.photobucket.com/albums/ag79/xcaliber95/WP_20150322_001_zps34oe3tgf.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/WP_20150322_001_zps34oe3tgf.jpg.html)

absolutely not. You can't replace film capacitors with electrolytic. did you check the rest of the caps? make sure the voltages and values match.

Well Ian I F'd up. I assumed I had a Sega MC2000 monitor. I still can't find anything other than the sticker on the tube that notates it is a Sega. I looked for the chassis info and all the post I have seen state that they have a MC2000. Anyway, back to the caps. I just started "shot gunning the caps". I will have to do some more research on the chassis. In the meantime, how would I identify the bridge rectifier?

Take a proper picture of the chassis and post it here. I'll be able to identify it.

The bride rectifier will 4 diodes placed closely together probably near where the fuses are.

(http://i1299.photobucket.com/albums/ag79/xcaliber95/WP_20150327_007_zpskbbsbbgg.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/WP_20150327_007_zpskbbsbbgg.jpg.html)

(http://i1299.photobucket.com/albums/ag79/xcaliber95/WP_20150327_006_zpssipqpiko.jpg) (http://s1299.photobucket.com/user/xcaliber95/media/WP_20150327_006_zpssipqpiko.jpg.html)

Sorry Ian, camera didn't do so well. If these are crap I can take a couple more.

Thats' a Kagi monitor.  a known pile of trash that was used often in sega cocktails

I will take it that I should chunk it? Also, I bought a Super Contra and just sold the PCB, but it has a Sanyo 20 - Z2AW. I think I can put that into the Frogger.