Pentranic, A L S, Nanao (all the same) 688 Monitor

[DavidsGames]

I purchased an A L S Marketing 19" monitor from a local merchant that had a stack of them at a killer price.  The problem is, there are NO schematis or diagrams available anywhere that tells me what the 5 Pins on the board are for.  They are laid out as 4 Pins, a space, 1 Pin, as a way to dummy proof the connection.

I managed to figure out that Pins 1, 2 an 3 are RGB respectively.  Does anyone know what 4 and 5 are?  My output from my game is RGB, Video Sync, Video Ground.  However I don't want to randomly assign the pins on this.  Any help available?

The current picture of the board is on Ebay (the Pentranic anyway)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190019355279

Bah, I can't remote link the pic from the FTP site, but the link above is good.

[Kevin Mullins]

I'll take a stab that the one all by itself is the sync.

But you should be able to easily meter the ground pin out to any ground spot.

[DavidsGames]

Oh I should have mentioned.  Unless I could not get decent connectivity, I tried a continuity test between the final 2 pins, and I could not get either pin to show that they were grounded to the chassis.  That leaves me to wonder if they are H & V Sync.  But I'd hate to guess and blow yet another chasses like I did my WG4606 (that's another story).

[Ken Layton]

Tech support at Pentranic can get you a schematic. Remember that Pentranic and Makvision merged over a year ago. Makvision is the current name of the merged company.

[DavidsGames]

I emailed Pentranic days ago, and have had no response.  I also emailed Nanao/Rodo and A L S Marketing.  I'm unsure if I gave Pentranic the correct display number according to their PN's only because this is an A L S; however the 688 numbering scheme matches the others (288, 888) that Pentranic has on their site.

[DavidsGames]

Well no luck so far, so I'll have to see if anyone can answer this.  On a trial and error basis, can I blow my chassis or game board if I...

1. Connect the Video Ground off the Game Board to the Sync Pin on the Chassis.
2. Connect the Sync Pin off the Game Board to the Video Ground Pin on the Chassis.
3. Connect the Sync Pin off the Game Board to BOTH the Ground and Sync Pin on the Chassis?

Since I do know the RGB, I'm ok there. But this looks like a nasty trial and error.

[grantspain]

i have never blown a chassis by mucking around with the sync and common,surely there are markings on that plug,if not and you are really worried just email pentranic in scotland(their tech guys up in the land of jocks are pretty helpful)-otherwise just go for it,its 50/50 chance of being correct first time-not bad odds-i reckon its rgb,common,sync

[DavidsGames]

Well, I did find the connections.  RGB, Ground, Sync. (Grantspain is right)

This lead to yet another problem (go figure).

The screen is too wide...

I see that there is a Red jumper wire on the board.  It goes to the Wide jumper, but the Narrow jumper is being taken by the high power return wire that comes off the CRT.  On older monitors, that's the wire that usually goes to the neck board.  I've been hesitant to swap them around, as there is an open pin ON the neck board, and still don't want to fry the chassis.

I am guessing that there is some type of switching system on the board that will make it possible to swap the Red and Black wires, as the Black should usually go to ground (if I recall things correctly).

[grantspain]

never heard of a high power return wire,what colour wire is it(black)does it go to the earth braid around the tube-on all monitors i have worked on you have an earth wire go from the crt to the neck board,usually a round pin or narrow spade connector-how about a lovely pic of mentioned connections and wires cheers very muchly

[DavidsGames]

Ok, on the 1st pic, you can see the 2 wires. The Red is plugged into Wide, the Black into Narrow.  the Black is the one in the 2nd pic that goes to the Braided wire. My friend described it as a return line, that goes to ground (as best he could describe).

The monitor kicks up just fine in that configuration.  Can I flip the Red/Black so that Red goes into Narrow?

The Neck board has that pin on it, but nothing is going to it.

[grantspain]

yeah surprised you ain't blown it up already,the black wire goes to the neck card pin,the red wire to either position on the width size-i am suprised the neck card does not have gnd or com written next to that pin-remove the black wire and place on the vacant pin on the neck card then place your red onto the narrow pin

[DavidsGames]

That's the configuration that the monitor came when I got it.  Black and Red wires where you see them.

[grantspain]

no,no you misunderstand take the black wire off the pin next to the red wire and put it on the pin on the neck card shown on the last picture,then move the red wire over to the narrow pin

[DavidsGames]

Heh, that's exactly what I'm going to do later today.  What I meant was that the monitor came out of the box with the Red and Black wires where you see them.  I'm wondering how I didn't blow a circuit.  Maybe I did blow the Narrow one, I'm unsure until I jumper the red wire to it and put the Ground into the Neck Board.

[DavidsGames]

Ok the question remains.  Did I blow the circuit?  The Wide/Narrow jumpers do nothing.  I can leave the wire off the jumper, or attach it to either one, and the picture is still the same.  That being, it's too Tall.  This is a Galaga, so you play up an down the screen.  I can see the top 3/4's but the bottom eludes me yet.

If I did blow it, is there a way to check the circuit w/a multimeter?

[grantspain]

don't know if you blew the width circuit,have you a width control pot (horizontal size) anywhere?

[DavidsGames]

There is a Horizonal Width coil, as well as H Pos and H Hold.  The Width coil does not seem to do jack. LOL

The guy I bought it from has 3 more (out of town), I suppose I could take my entire game there and test his other monitors to see if they work.  But this time I should check that Black ground wire to be sure it's going to the neck board.

[partsguy]

try www.alsmarketing.net   schematics are there series 1000/1100

[partsguy]

FYI: there were 3 Pentranic entitys worldwide, Indianapolis, Ajax Ontario Canada, and Scotland; the only current entity is www.pentranic.com in Scotland...they do have all schematics and parts......as for a Makvision/Pentranic merger...it never happened...Pentranic Canada went bankrupt in 2000...Makvision started on it's own employing some former Pentranic personnel......Pentranic USA closed it's doors june 2001......that should help with those questioning