ATC EQUIP PROB RADAR FAILED AND ACR X HAD LTSS FROM ACR Y. SYS ERROR.

Narrative

I WAS TRAINING ON THE W CTL AT SAN JUAN INTL. I WAS SEQUENCING ABOUT 6 ACFT TO FINAL FOR AN E OP. THERE WAS A LOT OF COASTING OF RADAR DATA BLOCKS. I VECTORED ACR X TO JOIN LOC RWY 10. HE APPEARED TO GO THROUGH LOC SO I GAVE HIM A VECTOR BACK TO THE LOC. AFTER ABOUT 30 SECONDS THE RADAR STARTED JUMPING AROUND. I OBSERVED ACR X STILL TRACKING SEBOUND AT LEAST 5 MI S OF LOC. I THEN VECTORED ACR X FURTHER NE TO JOIN LOC ACR X QUESTIONED THE VECTOR AND SAID HE THOUGHT HE WAS SUPPOSED TO JOIN. AT THAT TIME THE RADAR QUIT. MY INSTRUCTOR THEN TOOK OVER. WHEN THE RADAR STATED UP AGAIN; THE RADAR TRACK ON ACR Y CAME BACK UP N OF THE LOC HDG NE. MY INSTRUCTOR GAVE TFC INSTRUCTIONS TO BOTH ACFT BUT WHAT I GATHERED IS BOTH ACFT WERE RECEIVING TCASII ALERTS AND COULD NOT OR WOULD NOT ACKNOWLEDGE THEIR INSTRUCTIONS. I HAVE BEEN IN SAN JUAN FOR LESS THAN 6 WKS. THE RADIO'S ARE BAD; THE CTLR LAND LINES ARE VIRTUALLY UNUSABLE AND THE RADAR PRESENTATION IS FOR ENRTE RADAR AT BEST AND HAS NO PLACE BEING USED FOR A RADAR APCH CTL ESPECIALLY AT A MAJOR HUB. THE ONLY THING THAT SAVES THIS PLACE IS GOOD WX.