coliver80 Posted May 3, 2018 Share Posted May 3, 2018 So I purchased a Lynx lot at an estate sale. The lot included a model one lynx.. a model two lynx and 11 games. The model 2 worked but the controls were goofy. I fixed it by trimming a broke trace from the end of the controller board where it plugs into main board. The model one had massive battery corrosion in battery compartment that leaked onto the cartridge slot and the ac jack was broke. So I've cleaned the battery compartment and the game slot. when you put a game in the unit and power it on it comes one for a brief moment and clips back off again. Ive cleaned the corrosion from the battery compartment and game slot.. checked continuity on game slot.. checked for continuity between pins 31 and 33(might be wrong numbers). All that checked out. I checked the mosfet.. The large side(drain?) has 9 volts at all times with no voltage on the other 2 legs. Going to try to check caps tonight. I got this as an anniversary gift for the wife and so far I've gotten it all working except for this unit so any input would be greatly appreciated.. Thanks!!! Quote Link to comment Share on other sites More sharing options...
Andromeda Stardust Posted May 3, 2018 Share Posted May 3, 2018 If the Zener diode has failed, it will feed 9v to the main board and fry it. Not saying that's what happened, but it's a common failure mode. So I purchased a Lynx lot at an estate sale. The lot included a model one lynx.. a model two lynx and 11 games. The model 2 worked but the controls were goofy. I fixed it by trimming a broke trace from the end of the controller board where it plugs into main board. The model one had massive battery corrosion in battery compartment that leaked onto the cartridge slot and the ac jack was broke. So I've cleaned the battery compartment and the game slot. when you put a game in the unit and power it on it comes one for a brief moment and clips back off again. Ive cleaned the corrosion from the battery compartment and game slot.. checked continuity on game slot.. checked for continuity between pins 31 and 33(might be wrong numbers). All that checked out. I checked the mosfet.. The large side(drain?) has 9 volts at all times with no voltage on the other 2 legs. Going to try to check caps tonight. I got this as an anniversary gift for the wife and so far I've gotten it all working except for this unit so any input would be greatly appreciated.. Thanks!!! Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 3, 2018 Author Share Posted May 3, 2018 (edited) If the Zener diode has failed, it will feed 9v to the main board and fry it. Not saying that's what happened, but it's a common failure mode. Where is it located on the board.. is there a test procedure?? If its ZD1 I have 9volts on both ends. Edited May 3, 2018 by coliver80 Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 3, 2018 Author Share Posted May 3, 2018 K.. after some research I've seen where on model 2 you can add 5volts to c41 to test the unit.. as far as I can tell from diagrams it looks like c39 on model one is the proper test point?? Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 4, 2018 Author Share Posted May 4, 2018 Ok.. so by applying 5v 1a to c39 the unit powers up but says insert game on the screen whether or not there is a game inserted. What am I missing? Thanks! Quote Link to comment Share on other sites More sharing options...
+-^CrossBow^- Posted May 4, 2018 Share Posted May 4, 2018 If it still says insert game with a game inserted, then I would check all the traces and connections from the cart slot. You did state there was corrosion on that as well correct? The system simply isn't detecting a game in the slot still so would definitely check that. Could also be related to it not powering up normally so there must be a trace or several corroded out that aren't making contact where they should from the cart slot would be my first guess. Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 4, 2018 Author Share Posted May 4, 2018 If it still says insert game with a game inserted, then I would check all the traces and connections from the cart slot. You did state there was corrosion on that as well correct? The system simply isn't detecting a game in the slot still so would definitely check that. Could also be related to it not powering up normally so there must be a trace or several corroded out that aren't making contact where they should from the cart slot would be my first guess. There was no corrosion on the board.. just on cart slot and 1 battery terminal. I've checked continuity between cart slot and solder points on board several times. was hoping for maybe needing to add power elsewhere or possible bad resistor.. Quote Link to comment Share on other sites More sharing options...
+karri Posted May 4, 2018 Share Posted May 4, 2018 Sounds so familiar. I debugged ages on a similar Lynx. Until I decided to try another cart and it booted up perfectly. In my case the label on the cart masked a few contacts. Later I got the original cart to work also by pulling it out a little. Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 4, 2018 Author Share Posted May 4, 2018 Sounds so familiar. I debugged ages on a similar Lynx. Until I decided to try another cart and it booted up perfectly. In my case the label on the cart masked a few contacts. Later I got the original cart to work also by pulling it out a little. I've got 11 games that all work great on another system but all produce the same problem on this unit. I never did see the 5volt c41 done on a model one.. just model two. I looked at diagrams and assumed c39 would work as its in the same general area of the diagram as c41 on a model one and has the same specs.. maybe there is something else different on the model one or perhaps something got damaged by having 9+ volts on the mosfet drain?? Quote Link to comment Share on other sites More sharing options...
+karri Posted May 4, 2018 Share Posted May 4, 2018 As you get INSERT GAME the Suzy, Mikey and RAM works. The problems may be in dried capacitors. At least you need to change the ZD1 as it is broken. Just changing the big caps 470u and 100u could be enough to boot the cart. I also read somewhere that the 10u cap close to the edge connector is a critical one. I did fix one Lynx I with the INSERT CART just by re-capping it. Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 4, 2018 Author Share Posted May 4, 2018 As you get INSERT GAME the Suzy, Mikey and RAM works. The problems may be in dried capacitors. At least you need to change the ZD1 as it is broken. Just changing the big caps 470u and 100u could be enough to boot the cart. I also read somewhere that the 10u cap close to the edge connector is a critical one. I did fix one Lynx I with the INSERT CART just by re-capping it. First off thanks for your help.. I'm about at my witts end and I have less then a week to fix this if I'm to have it ready in time for my wife. I did'nt recap it but i did pull the caps and test them and they all tested fine. Console5 sells a kit with mosfet, zd1 and some other transistors.. i know that will fix power issue.. but would be waste without fixing "insert game" error. Quote Link to comment Share on other sites More sharing options...
Lord Thag Posted May 4, 2018 Share Posted May 4, 2018 Just like to add that a Lynx as an anniversary gift is awesome! My wife surprised me with a boxed Astroboy for GBA one year (I'm a huge shmup fan) and I was pretty blown away. Was like.... how did you know to even get that!? Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 5, 2018 Author Share Posted May 5, 2018 Just like to add that a Lynx as an anniversary gift is awesome! My wife surprised me with a boxed Astroboy for GBA one year (I'm a huge shmup fan) and I was pretty blown away. Was like.... how did you know to even get that!? Lol... thanks! So far its a model 1 lynx a model 2 lynx 11 games the small lynx case and the large lynx case. Ive gotten everything working but the model 1. Quote Link to comment Share on other sites More sharing options...
+karri Posted May 5, 2018 Share Posted May 5, 2018 Also take a look at the pins in the cart connector. A sharp edge may have bent a pin. You can straighten it back again with some dentist picks. Cold joints on the cart connector pins? That have been broken during the years? Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 5, 2018 Author Share Posted May 5, 2018 Also take a look at the pins in the cart connector. A sharp edge may have bent a pin. You can straighten it back again with some dentist picks. Cold joints on the cart connector pins? That have been broken during the years? Check, check and check.. checked caps yesterday going to check resisters today. May end up having to give it to her broken. Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 6, 2018 Author Share Posted May 6, 2018 Resistors check out. I checked continuity between cart slot and solder points on main board. All checked out. Was going to check from solder points to other points on board but am having a hard time figuring out what processor pin numbers are D0 or A0 for example. I'm home for the weekend till Monday and Lynx is at work so may take a brain break and play some H.E.R.O.... lol Quote Link to comment Share on other sites More sharing options...
+Stephen Moss Posted May 8, 2018 Share Posted May 8, 2018 I checked the mosfet.. The large side(drain?) has 9 volts at all times with no voltage on the other 2 legs. Going to try to check caps tonight. I got this as an anniversary gift for the wife and so far I've gotten it all working except for this unit so any input would be greatly appreciated.. Thanks!!! If the output of pin 10 on U6 is 0V and the Lynx power LED is on then you should be able to measure some voltage at the Gate, if you are measuring 0V on the gate then the MOSFET should be off, the power LED should be off and I would you to measure 9V. Where is it located on the board.. is there a test procedure?? If its ZD1 I have 9volts on both ends. You have to be careful how and where you measure this to get an accurate result due to the design of the Lynx as it is the power (9V) supply that is common throughout the system, not the 0V line. consequently if the Lynx is on and you can measure 9V between TP15 and the Anode (not the end with the back line) of the Zenner then either the Zenner is dead or someone has done that horrible connect the headphone ground to the power supply ground hack. If you look at the circuit diagram where the cartridge port is to the right of it is two ICs, a 74HC164 & a 74CH4040. Check those out of you can, you really need an Oscilloscope for this but a basic operational indication could be indicated with a multi-meter. 74HC4040, with the COM lead of your multi-meter on pin 8 and the Lynx powered on you should measure the following voltages... Pin 16 = 5V Pins 11 & 10 probably somewhere between 1 and 4 volts depending on how fast the are switching. 74HC165, with the COM lead of your multi-meter on pin 7 and the Lynx powered on you should measure the following voltages... Pin 14 = 5V Pin 1 = 5V Pin 9 = 5V Pins 2 & 8 probably somewhere between 1 and 4 volts depending on how fast the are switching. Also measure the switched cartridge supply voltage at TP20, again you will probably read somewhere between 1 and 4 volts depending on how fast the are switching. Quote Link to comment Share on other sites More sharing options...
coliver80 Posted May 10, 2018 Author Share Posted May 10, 2018 Thanks for all the help! With a little time and some parts form cowdog 360 everything is ready for Mothers Day/Anniversary. Thanks Again!! Quote Link to comment Share on other sites More sharing options...
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